Visitor
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4 Messages
Email down for two weeks (routing issue?)
I have been unable to check email for over two weeks, since approximately 16 April 2022, while on the Comcast network. When I switch to my non-Comcast cell phone's mobile network, it works fine. The problem might be a routing or ACL issue on the Comcast network near Hillsboro, Oregon. It doesn't matter if I try on the web or with Outlook, my computer cannot contact two critical Comcast servers related to email. Can a Comcast network engineer look into this (as I've already rebooted my modem)? I'm trying these forums hoping for a Comcast employee because I don't have 2 hours to burn with phone support telling me to defrag my hard drive and there's no email support option. I've also run these same tests from my Comcast modem's diagnostic screen. This problem is definitely not my computer or my home router. All other functions of the Comcast customer portal work fine, it's just servers related to email.
xfinityconnect.email.comcast.net 96.116.237.39
mail.comcast.net 96.116.224.161
My IP address is currently: 71.59.xxx.yyy
tracert xfinityconnect.email.comcast.net (when I try to access email from the web portal)
Tracing route to xcp.ge.xfinity.com [96.116.237.42]
over a maximum of 30 hops:
1 <1 ms <1 ms <1 ms 192.168.0.1
2 2 ms 2 ms 2 ms 10.0.0.1
3 14 ms 14 ms 11 ms 100.92.102.3
4 10 ms 11 ms 11 ms 162.151.214.245
5 12 ms 11 ms 11 ms 24.124.129.169
6 24 ms 48 ms 25 ms 24.124.129.165
7 20 ms 19 ms 16 ms be-36211-cs01.seattle.wa.ibone.comcast.net [68.86.93.49]
8 26 ms 23 ms 19 ms 68.86.93.66
9 32 ms 31 ms 34 ms et-3-12-1-as03-d.hillsboro.or.ndchlsbr.comcast.net [162.151.200.114]
10 30 ms 30 ms 31 ms et-5-1-1-s05-d.hillsboro.or.ndchlsbr.comcast.net [162.151.200.98]
11 * * * Request timed out.
12 * * * Request timed out.
13 * * * Request timed out.
tracert mail.comcast.net (when I try to download mail with Outlook)
Tracing route to imap.ge.xfinity.com [96.118.17.82]
over a maximum of 30 hops:
1 <1 ms <1 ms <1 ms 192.168.0.1
2 2 ms 2 ms 1 ms 10.0.0.1
3 11 ms 11 ms 11 ms 100.92.102.3
4 12 ms 11 ms 11 ms 162.151.214.245
5 12 ms 14 ms 12 ms 24.124.129.169
6 21 ms 15 ms 15 ms 24.124.129.165
7 20 ms 20 ms 18 ms be-36221-cs02.seattle.wa.ibone.comcast.net [68.86.93.53]
8 22 ms 30 ms 22 ms 68.86.93.70
9 32 ms 31 ms 29 ms et-50-1-sas02-d.hillsboro.or.ndchlsbr.comcast.net [96.110.86.62]
10 23 ms 21 ms 19 ms 162.151.201.186
11 31 ms 30 ms 29 ms et-3-1-1-s33-d.hillsboro.or.ndchlsbr.comcast.net [96.108.16.26]
12 * * * Request timed out.
13 * * * Request timed out.
14 * * * Request timed out.
Accepted Solution
user_1a9c8d
Visitor
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4 Messages
5 m ago
Oh <Edited: “language”> Comcast... so I've definitely traced the problem here and it's jumbo frames. For some reason as of about 2 months ago, Comcast mail servers (and so far only the mail-related web and POP/IMAP servers) will not pass any traffic when I've got my MTU size larger than 2KB. Set it to 3KB or higher and traffic stops. I have my whole house set to the maximum 9KB MTU so that backups and other traffic on my wired LAN fly. Any server on the internet is *supposed to* negotiate the frame size down to whatever is mutually agreeable, which is why I generally don't have any problems. Comcast's mail infrastructure might have some poorly functioning IDS/IPS rule that's tripping on MTU negotiations that it deems are a threat. i.e. it is dropping the traffic vs. negotiating the frame size as required by the IETF RFCs. Argh!!!
(edited)
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BruceW
Gold Problem Solver
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24K Messages
5 m ago
Please see https://forums.xfinity.com/conversations/email/cant-pop-to-any-comcastnet-address-mailcomcastnet-pop3comcastnet-and-imapcomcastnet/602daffdc5375f08cd1e869a.
What happens exactly when you try to view https://connect.xfinity.com/?
Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.
(edited)
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user_1a9c8d
Visitor
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4 Messages
5 m ago
OK, so if I get a TCP test succeeded, it can't be a routing issue. Maybe an IDS/IPS issue that's shutting down the connection? I'll try doing something to change my Comcast IP address somehow.
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BruceW
Gold Problem Solver
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24K Messages
5 m ago
I don't believe I've ever heard of that, and can't imagine why it would be unless Comcast is blocking you for some reason.
If an employee doesn't reply to your message here, Comcast Security Assurance might be able to help. You can reach them at 1-888-565-4329 (from https://internetsecurity.xfinity.com/help/report-abuse/). Note that this is NOT one of the general customer service numbers.
The first-line reps there are sometimes not very helpful, so you may need to be persistent and keep at them until you get a satisfactory answer.
(edited)
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user_fd6480
Visitor
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3 Messages
3 m ago
I had the same problem on my desktop PC using an ethernet connection. On April 29th I stopped recieving email on outlook. email continued to work on my phone. I also found if I went to xfinity.com I could log into my account and see my billing details but if I clicked on email, I would get a timeout. on my laptop through a wireles connection I could access my email. I found the fix was to disable jumbo frames on my desktop NIC. I have no idea why this stopped working. I have always had the jumbo frames set to maximum, with no issues and suddenly my email stopped working on 4/29/22. Something similar happened about a year ago, and I wasn't able to diagnose the problem and then it fixed itself. I think there is something going on at xfinity. xfinity tech support was of no help on either occasion.
Xfinity please fix this!!
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