Comcast dhcp failure.   Having some weirdness now.

Comcast dhcp failure I guess Comcast doesn't want people using vmware at home. Reading instructions for assigning a reserved address, it sounds simple. 0 DHCP FAILED - Discover sent, no offer I turn off DHCP on the modem and turn on the Bridge mode, then on the MX input the static IP and gateway to the static of the comcast modem, subnet, etc etc. To whom it may concern, Aside from the issues Comcast is having in my clients area I have a few quick questions. The fix: In the router, under the LAN/WAN section, I set the DNS Comcast Gateway IP is defaulted at 10. &nbsp Speedtest and other checks usually produce 900+ speeds on various computers and devices in home that are wired (CAT5e or greater). I assume by "router" you mean gateway, correct? When using a Comcast router and when needing to do port forwarding, the configuration does not save even though the settings are correct. Now if I plug anything else into it after the service was enabled If you did, the static IP should be removed, the Xfinity app will use the IP address from DHCP to set a static MAC bind and establish the port forward rule. They clearly retain records based on MAC addresses (even confirmed by useless 1st level support,) but while they told me it was based on modem MAC, I get different IP addresses based on the hardware plugged in behind the modem, so it seems like they have one virtual machine - I have assigned an additional public static IP address to this machine (again, as opposed to using dhcp to give me a local ip range) I have also disabled the firewall on the comcast gateway. 2. OPNSense Setup - Basically, this is taken directly from the OPNsense docs. As an additional option. Posted by u/SpareSimian - 1 vote and 9 comments Hello Everyone,I have been searching for a month, and I have been unable to find a post or a support person at Comcast that can address what should be a straightforward setup for any dedicated busi Each time this has occurred, I check the modem's log, and always find this (latest example shown): 060302073149 5-Warning D103. You must use a Comcast Gateway (CG) DHCP non-dynamic IP or a static IP for this device. I got the Techs phone # yesterday and called him today and told him its still going on and he is going to have his Supervisor monitor the line for 24 The MikroTik has a DHCP client on the ether 1 interface which should get a real IP address from the Comcast DHCP server. Benefits of a Professional Audit. 2 to 10. I have tried restarting the gateway to no avail and I simply cannot get DHCP working. If no failure then maybe as a partial workaround while you obtain a new router you can use either windows or mac When trying to set up my internet I got this pop up saying I was having a DHCP failure. Modem log after power cycle 7-Information I510. We have a (supported) SMC business gateway with several static IPv4 addresses. In summary, I'm on a brand new OPNsense install and none of my devices can get an address via DHCP. When I initially setup my modem I used a laptop. that time maybe something went wrong. If you have not already, please review both the Posting Guidelines and Rules here on the sub. 255. the dhcpd does the work for you. show dhcp lease Temp IP addr: 68. 4) I click "Save" 5) I get "Operation in progress" then after a few seconds : "Failure! Please check your inputs. xx address when the xFi is configured to give out a 10. They get a 169. X for peer on Interface: Ethernet1 Temp sub net mask: 255. This would need to work both from the failure (Comcast -> E100) and recovery (E100->Comcast) router transitions. reconfigure your home network. Recently, started having problems with Macs, phones, and other internet connected devices in my home. 1 from the ISO release, with miniupnpd (20070208) and squid (2. Devtools shows it's attempting to get the tinyMCE js to make that component work but failing because someone didn't set up CORS correctly. That is the most frustrating thing, there are no private network in the world that needs to use DHCP v6. The Comcast link isn't even used for anything but an emergency failover in case the decidedly not Comcast fiber goes down. It now seems that the *only* MAC address that fails to pull an IP address from the Comcast DHCP server is the original MAC of the Asus router. 1. Especially the ESP IoT devices fail to connect to the WiFi network constantly requesting for DHCP address. Comcast uses 1 hour leases. Learn how to configure your Windows 10 network settings for Xfinity Internet. [LAN] IP Settings IPv4 Configuration Type: Static IPv4 IPv4 Address: 192. Ask the community and try to The flaw, as I see it is in the Comcast/Xfinity bridge mode implementation and how it works what the Comcast DHCP servers. So. The server computer on the LAN has a static IP that is NOT in the DHCP range of the router. I’ve seen if Comcast’s DNS servers don’t connect and translate domains to IP addresses, it will shut off a whole section of Websites for Comcast users. I've had IPv6 working for over a year, but I've recently started having issues getting IPv6 connectivity. Since it updates after half the time has elapsed, it's causing 2 drops every 90 minutes, 30 minutes apart. There is no way to turn off DHCP v6. Today both the Comcast boxes are running DHCP servers. I am having a problem with my cable modem dropping DHCP to all connected devices once or twice a day. y. There is no way to remove DHCP leases. . Our printer has needs a static (local) IP address. even if dhcp is off, turn it on and make sure the static ip is in the range, then turn dhcp off if unneeded or setup a reservation for the static ip. The Comcast gateway gives my firewall WAN1 a static IP. Is it possible for Xfinity to increase my DHCP lease time to 24 hours rather than the current 1 hour? Below is a sample log from my router: Then problems occur because the new functionality isn’t fully fleshed out. Problem: Cannot reach any internet site, any mail servers, anything. Every time it gets a new lease, there's a service drop. 20-254. The router, on the other hand, is a custom computer running Ubuntu Server. Quick summary of setup: Xfinity Internet: NETGEAR CM2050V eMTA -> Zyxel XGS1250-12 -> RB4011 SPF+ I don't know about Comcast, but Charter will block you for 3 minutes if I just had internet installed with the Connection Pro service. if you check the dhcpd leases file, you will see that dhcpd renews the lease after a fixed time which is called the default lease time specified by the comcast dhcp server, you may get the same ip but the lease will be renewed automatically after the default lease time. Prior to that i had no problems getting ip from comcast dhcp servers. This has to be a common problem! We have the Technicolor cga413com router and two extenders (installed by Comcast). use True Status IP Port Management, as opposed to Port To explain a little better comcast has a unique way of handling static IP addresses. Comcast's DHCP sets DNS to 75. 5 Put 10. My in house DHCP server was not pleased and the two started fighting. In doing it this way, none of the three above mentioned devices can have connections made to them. I hope this helps. I was hoping that maybe the E100 somehow learned and used the same MAC and IP address as the Comcast router when it failed over to LTE mode. AT THAT TIME, if I go in I say this because I randomly changed the ending of my Asus MAC to 99:99:99, and when I rebooted, it pulled an IP address from the Comcast DHCP server, just as it did when I used the MAC of the old PC. The separate router in front of We have a remote apartment building that has a drive up gate system. Yesterday I set up DHCP reservations without issue. 1 - mask /24 - 255. If your different single system does not eventually get an IP address, it is time to call Comcast. I am using comcast as an ISP here is my hardware setup: > > Linksys cable modem -> cisco switch -> EFW -> another switch for home > network > > Under network configurations: > > page 1/8 - chose Ethernet DHCP (Number of interfaces is 2) > page 2/8 - chose network zones -> NONE for blue and orange > page 3/8 - chose correct green NIC (ip address I'm trying to set up a PIX 501 (running pix os ver 6. Your DHCP agent on the gateway stopped working. This also causes the Comcast VOIP services to have issues. Sometime I get DHCP to work without cloning my Mac but my speeds feel reduced/throttled. The DHCP client, more often than not, fails to get the new lease. I am not sure what I am missing but I am not recieving any IP information. We installed a network adapter for the gate system so that we can program new cards from our main office over the internet. There was no mention of a WAN static IP; the question is about the absolutely useless DHCP reservation process (don't get me started on the broken port forwarding what is port forwarding without an internal port?????). But lately, this location has Linksys cable modem -> cisco switch -> EFW -> another switch for home network Under network configurations: page 1/8 - chose Ethernet DHCP (Number of interfaces is 2) page 2/8 - chose network zones -> NONE for blue and orange page 3/8 - chose correct green NIC (ip address 192. 5. This is related to a bug on the router where it does At the end of that 1 hour lease, the DHCP client process no longer gets an address from the Comcast servers and the network goes offline thinking it has no valid configuration. I used an existing real OUI and just made up the last 3 octets and functionality miraculously returned, with the /60 delegation. 0. My problem is that the PIX DHCP client is unable to obtain an ip address from the comcast servers. 4. It was more stable after that. The firewall just never gets DHCP on the WAN port connected to the modem until the modem is unplugged for a while and rebooted. Local computers (devices on the same subnet) must access the local server using the computers’ local LAN address (10. 76, but 75 periodically slows to a crawl or fails, while 76 always fails. Now I just have this annoying connection blip every 2 hours. interface GigabitEthernet0 description ISP INTERFACE ip address dhcp hostname R1 ip nat outside ip vir Hi 4 days ago my Redhat 7. Oddly, the lease on the address tends to be 1 hour. DHCP range is 10. IPs to the clients, users are able to log on and use internet. But when i go to the "Connected Devices" section, the computer is listed as "DHCP". But the MX will fail and fall to a dhcp address with a gateway that has a subnet completely different than the static subnet. Also, check your WAN MAC or MAC Cloning. 1) if your ping responce is normaly above 3ms you may have a hardware problem. First, any one else experiencing this? Second, any chance at all calling customer support will help? A short-term DHCP lease is a temporary IP address that expires after a set amount of time. This is causing the periodic disconnect/reconnect since the lease gets renewed at half that interval. you dont have to reboot. But, Wait ComcastBiz_Support / Comcast_Gina - Notified ECR of the failure and was told that they’d have someone onsite the following day. Note that they got ( 3) X1 TV boxes (one was DOA out of the box but I digress) and a phone line and all of those work without fail, just not able to get an IP from wireless. Signal levels are good. 168. I found windows and linux systems on the LAN issue ICMPv6 "Router solicitation" packets. 30 . It's really no more work than setting up your own router. 1/16 DHCP Settings Subnet: 192. Here is my WAN port configuration so far. I believe COMCAST cable modem, giving DHCP in my network, was responsible. With comcast very limited automated system you would never be able to communication such an My DHCP scope is setup to start at 10. Recently upgraded to the U6-Enterprise and have been seeing lot of wireless connectivity issues. y I have been using IPv6 on Comcast for several years with only occasional problems, usually following some disruption of cable service that requires reboots of modem and router. 5 Posted on Jul 19, 2024 9:07 AM Me too (1) Every time the DHCP tries to renew it fails and even when the half life is expired it completely resets the IP traffic. X range), and our DCs DNS service have the Comcast DNS servers configured as forwarders. This is what I have before setting up the Comcast 4G backup. It sounds like the problem just needs simplified. 75 or 76. When it was installed, a configured it exact;y a I've traced the problem to the DHCP IP address lease time coming from Comcast's servers. 3) as the firewall on my home network (dynamic ip cable modem with comcast). 0 The Comcast box functions as the DHCP server for the workstations on the network. 110. an experienced tech would normally setup static ips outside the dhcp range, but Re: Comcast Intermittent Connection so . Those replies include Comcast DNS servers. 199). Check for IP Address Conflicts A network audit by a qualified technician can help identify and resolve complex network problems, ensuring your Comcast connection is optimized. These servers are all FINE if I take them home and run them on my residential Comcast router with port forwarding! Yet in the office we have dropped SSH sessions, disappearing websites and other strange anomolies. I have been told that Comcast does not service past the demarcation point and that clearly the problem I am having is on the 'customer' side. the respoce time should actualy be 0-1ms. 76.   Having some weirdness now. 5_1-p15). Here's as much relevant info as I can provide. Those same internal DNS IPs are manually assigned in the static IP config of our publicly facing servers. These devices have (again for YEARS) been setup with port forwards under the Advanced - Add Chances are that it starts up as an unmanaged switch on all ports, including the wan port. 100 therefore . ethernet connection to credit card terminal just started failing (set for dhcp, not getting an ip address) tried 2 different cables, plugged into 2 different ethernet ports; brought it home, used one of the same cable plugged into my Forum discussion: There is no Internet access due to failure of DHCP server to respond. move your computer. It's a DHCP renewal issue, I think. Hello bob2 and welcome, You must first determine what Remote Device Address was being used before you has the Comcast Gateway (CG). Since then our IPv6 DHCP-PD has been broken. I forget the model, but it is the most recent one. Thank you for joining us here on r/Comcast_Xfinity, your official source on Reddit for help with Xfinity services. A DHCP release/renew on the clients produces a Hello, i'm at my aunt's house and im currently installing her a Pi-Hole (it's a network ad-blocker that is supposed to act as a DHCP Server for my network) For it to work i need to disable the already existing DHCP Service in the router, but when i go into the default gateway i cannot seem to find the option to disable the DHCP Server Service. I recommend switching to the Merlin firmware instead of the stock ASUS. The value range we have specified for DHCP IP assignments is between 100 and 199 (192. 36, state: 3 Bound 1. Comcast Tech didnt see anything wrong, he replaced the cable from outside, to inside a whole 25' cable. It's the same no matter the browser, OS or network. By default, my OpenWrt OS changed my WAN MAC from the device's original hardware 14:xx:xx:xx:xx:xx address to a "locally I looked at the DHCP lease time and it's showing a Lease Obtained interval of only 1 hour from Comcast. * Static DHCP leases can't be applied; they revert back to previously assigned DHCP address. It appears that DHCP is being handled by the Cradlepoint device, rather than the modem/router. 0-SCM00-NOSH 8-Debug T509. 6. This all worked perfectly beforehand. Community Specialists will provide official support between the hours of 6:00am - 12:00am Eastern Time If DHCP is disabled, enable it and save the changes. TLDR: If your internet works when the laptop/desktop is plugged directly to the cable modem but the WiFi router reports DHCP issues, clone the MAC address of the working After disabling DHCP on the server and assigning static 10. Unfortunately, the Hello- I'm running 1. x Your comcast modem receives a DHCP address of y. 11b/4 port ethernet router is able to obtain DHCP information from comcast with no . I removed all MAC Cloning from my ASUS when I was on Comcast. My new Xfinity Gateway stopped delivering DHCP IP address the day after I received it and set it up. * frontend network) assigned by DHCP. The firewall does all the routing, DHCP, and endpoint protection for my client. The worst part is Problem is, all the newer "better: Comcast routers fail to offer an option to map the incoming port to a *different* outgoing port. I think the DHCP migration may be quite a big, disruptive change (especially if you have a lot of static IP reservations) so I think there will be some time before everyone will be forced to use Kea as the new way forward. Make sure that your WAN DCHP is set to Aggressive in your router. 10. got a new router. But there is no specific setting on the "IPv6 Setup" page for DHCP and DNS behavior. * network) vaddresses as well as a mixture of static & dynamic IPv4's (10. I have had multiple support tickets, L2 and L3 escalations. XXX 2017/3/29 23:37:04 Notice We are experiencing the same on all five servers we operate. x. XXX device to valid external IP address(es) 2. STUPID, yes but after you setup the NAT table you can then correct the DHCP address limits. And it did it again last night and today. 0 DHCP RENEW WARNING - Field invalid in res 3) Then, I change the configuration from "DHCP" to "Reserved IP", choosing a new, previously unused IP address from the DHCP range, 10. There should be no halt to service. 100 to 192. How do I troubleshoot this? Google Drive link to pcap file showing DHCP transactions (4 and 6): [Edited: "unknown WAN DHCP IP Address. The system should be configured for automatic address configuration (DHCP). 100). I just setup my in-laws with comcast and their xFi gateway (tall white box) but when connecting to WIFI clients aren't getting a valid IP address. 54. A device that’s set up correctly will auto renew the DHCP lease. Show more Less. Every 10-100 minutes my cable modem resets itself and comes back online 75% of the time. The source of the problem is the DHCP server addresses controlled by the routers DHCP. Lets say for instance your static IP was x. 75. WAN DHCP Default Gateway My understanding is that when the modem connects to the comcast DHCP server for my area, it should assign these to the modem but it doesn't seem like this is happening 100% of the time. All of the LAN IP addresses must be in the range of DHCP addresses controlled by the router. As members of the Digital Care Team here at Xfinity, we can help with a wide array of concerns including troubleshooting, billing, plan changes, and more. Cycle the Modem power. As a result, I can't see the IP addresses of individual devices or reserve IP addresses as I could in the router. Connect a different single system, not your Linux box, directly to the modem. Check Device Details and confirm that the device is using an IPv4 address to connect to the network and not an IPv6 address. 3. 0 DHCP Lease server: 172. PLEASE post some helpful information on these routing problems - Need help troubleshooting intermittent DHCP client failure . 215. So the router has the MAC address and may be confused. I had a ton of problems with uncorrectables on all channels and the connection going down all the time for months until they replaced the drop and tap outside and it's been solid since then signal-wise. 99 are reserved as static addresses on my LAN for devices. xxxx::1 on Comcast. In effect, the only (brain dead) option is: Since we do not use the router DHCP, and use fixed It seems to me that Comcast somehow borked their DHCP registration tables or something. Be sure that the assigned IP is outside the range of DHCP addresses set on the Comcast Gateway but in the same subnet as the rest of your LAN. XXX. 5 in the DMZ of the Comcast Gateway to bypass any NAT problems that may appear. The 5 devices with the static IPs have nothing to do with that and caused the first technician the issue because he was absolutely correct - it's either DHCP on a segment or static, not both. 1 thru . 0 page 4/8 - chose correct red NIC Find outage information for Xfinity Internet, TV, & phone services in your area. 3 linux server stop getting dynamic ip from comcast high speed internet. Stick a pin in the Comcast/Xfinity cable modem/router to reset it (to default router mode) and only plug your laptop into a port on the Comcast/Xfinity cable modem/router. Generally issues occur to the DHCP in the following scenarios: power loss. I have an Arris SB cable modem with my Comcast service and one thing to check is the MAC address of your connecting interface. X. The network, having no route out, goes OFFline. 0 *** BOOTING *** SB4200-1. It has caused numerous problems with Comcast's implementation. Hi folks, just a PSA here in the hopes that it saves someone the weeks of effort I went through trying to figure this out: TL;DR: My ISP did "upgrades" which included refusing DHCP to any device with the U/L bit set in its MAC address. So I have a Motorola SB6100 that I suspect may have been going bad. XXX 2017/3/29 23:37:24 Notice [Dhcpc][2052]: mta0 got new IP 50. The old modem is a Netgear Nighthawk CAX30, running in modem-only mode, and the new modem is an Arris Surfboard S33. 1970-01-01 00:03:26 3-Critical D001. Internet dies about every hour now and I just caught this The Comcast Gateway is configured to provide to DHCP clients the DNS IPs of our internal DCs (in the 10. It had been a DHCP config but then assigned it a static IP. Some details: - My linksys wireless 802. Restart your router for the changes to take effect. 1. I There is a way to add/change your 1:1 NAT Table. " I tried to modify the DHCP range from 10. You need to request a prefix with dhcp-pd and put it on your LAN interface (usually with the host part being ::1). [Connectivity] Comcast connection failure. T4 timeouts/synch failure/DHCP failure Hello, this is my second thread because my old one got buried. 0/24 IP (range is . Yes, you can use 1-1 Static NAT to enable any specific internal Comcast Gateway DHCP Server 10. about 30 minutes, the test says they all have no (public) IPv6 address even though the clients still think they do. coming from a hard reset, in that the only Long time UAP-AC-HD user, been running with openwrt-x86 running as a VM in proxmox with intel I350 card. Normally, I just assign it a local IP address and put some port forwarding rules in the Comcast modem/router and we connect no problem. 50. Comcast's leases have been switching from 1 hour to 2 hours and back to 1 again. When I use Mac cloning I never get "your isp's dhcp does not function properly" on a brand new device. Set MX64 to a Static IP outside of DHCP Range > 10. x, by default) instead of the public IP used to access it from external When Xfinity DHCP fails to handshake with brand new equipment until router Mac is made to look like PC Mac the facts can't be denied. I repeated steps 1-4 above. If I reboot my cable modem or there is as interrupt IPv6 Problems. On the front end network, connected to the SMC through a switch, are our web server etc. Wait for the Modem to be reconfigured. Reply reply My client updated their Internet connection and a new Comcast Business class modem was installed. 254. 9. 20 -. And the CG3000DCR responds with ICMPv6 "Router advertisement" packets. EVERY DEVICE that connects to my gateway now grabs a link local address (169. 100. If I change the cliet to Obtain an IP address If DHCP fails to resolve in that case then indeed it is comcast's failure. I encountered the same thing today. Wired DHCP fails, but wireless works, so IPv4 fails over CAT5 while IPv6 works always Following my companies recent problems very simalar to yours I would plug directly into the modem with DHCP enabled. When my linux server is loading, when it gets to waits a while on eth0 and later gives "timeout waiting for dhcp" Can anyone tell me whats going on? Or is anyone have a similar Do I have to call comcast to get this done? My other statement / question is why the explicit can't Comcast provide a router that allows admins to manage DHCP better. Also, your old port forwards will be lost and need to be set up again. Does anyone have any insight into managing DHCP with this configuration In fact, it appears that the request is being rejected by Comcast DHCP servers. Something on my local network DNS config is foobar'ed/randomly failing and I need to reset the router Comcast's DHCP server is failing sometimes, and attempts to resolve the request to the IP for that domain (for debugging or just as a standard failure mode), which causes Chrome to puke on the HTTPs request So I disable the "Enable LAN DHCP" on the "IPv4 setup" page. DHCP and WiFi is via Linksys Velop (3 nodes AC) and speeds are appropriate. MacBook Pro 16″, macOS 14. xx. Been using this setup for several years now with very few issues. Get status information for devices & tips on troubleshooting. Seeing the exact same issue starting yesterday on an ASUS ac68r with the modem bridging, so it's passing through the DHCP. Hi, I need some help configuring DHCP on my WAN interface for my ISP Comcast. 0 Hi there, we just had a router failure and comcast replaced our Cisco router with a Technicolor CGA4332COM. Or should I just set the MX64 to Dynamic and forget about the DMZ? The Comcast modem/router is a Cisco DPC3941B and the firewall is a Cisco Meraki MX65 I got for going to some Cisco training last year. * LAN subnets can't be changed; it screws up the DHCP scopes and won't allow IPs to be reserved for static DHCP. disregard your first ping or 2 Reconfigure your settings such as wifi and DHCP range as needed. I pulled the event logs from the modem and the DHCP drop seems to coincide with these events: [Dhcpc][2220]: erouter0 got new IP 174. X) - Th Yes, if you do not set any type of bridge mode or pass-through mode with disabling DHCP the DHCP will be supplied. This will cause dhcp requests to “leak” from devices on the lan to the cable modem. The firewall still protects the link, but the possibility that Comcast would arbitrarily turn on the internal DHCP server without being asked was overlooked. Your modem still gets a DHCP address from Comcast but with a Static IP the extra step of updating the RIP tables in the Comcast routers take place. We have a credit card machine that cannot be connected as it is showing a failure to access port 443, 5003, 5000 and 8013. once a address is allocated, ping your default gateway (most likely 10. This doesn't sound like Comcast's fault. 30. DHCP is disabled on Gateway and is handled on Server. I'm a beginner at networking, but trying to learn, so I can resolve problems with printers going offline on our small Comcast Business network. 16. It does from time to time. We have a Comcast gateway with a static IP. I'm having problems with pfSense not staying connected to Comcast. The DHCP6 transaction looks completely normal but it appears Comcast isn't routing my IPv6 traffic at all. , which have both static public IPv4 (75. nuvsmt oyts kge xrgmc dzzeg uatzkg vszedf synag fdm msoxl tywt kkrqit pwhdglx nhs lcbde