BTinternet problems?

Mailman List Mirror (Read Only)
1

We're receiving multiple complaints about problems reaching anything @bt. Is anyone else experiencing this?

I.E. e-mails to @btopenworld and also @btinternet.com are bouncing. The root cause seems that we are unable to resolve anything within bt.com et al. For whatever reason, this is affecting all of the netblocks that we have nameservers in, but not some others we control.

I.E. working ok from 204.188.96.0/20:

% dig @194.72.6.52 bt.com | grep ^bt
bt.com. 1D IN A 62.7.244.126
bt.com. 1D IN NS dns1.axion.bt.co.uk.
bt.com. 1D IN NS ns1.bt.net.
bt.com. 1D IN NS dns0.axion.bt.co.uk.

Not working at all within 208.139.192.0/20:

ns2# dig @194.72.6.52 bt.com

; <<>> DiG 9.2.1 <<>> @194.72.6.52 bt.com
;; global options: printcmd
;; connection timed out; no servers could be reached

At the same time...

ns2# tcpdump -n -s 1600 host 194.72.6.52
tcpdump: listening on xl0
10:40:07.235635 208.139.192.2.36647 > 194.72.6.52.53: 17495+ A? bt.com. (24)
10:40:12.241697 208.139.192.2.36647 > 194.72.6.52.53: 17495+ A? bt.com. (24)

ns2# traceroute 194.72.6.52
traceroute to 194.72.6.52 (194.72.6.52), 64 hops max, 40 byte packets
  1 cw-gw (208.139.192.1) 1.255 ms 5.908 ms 1.216 ms
  2 denver-core-fe-0-0 (206.168.230.5) 7.285 ms 2.721 ms 2.597 ms
  3 den1cspdaa02-v200.denver.terabeam.net (216.137.18.229) 4.406 ms 2.355 ms 6.978 ms
  4 den1mcoraa01-ge110-v101.denver.terabeam.net (216.137.17.149) 1.261 ms 4.901 ms 7.538 ms
  5 den1pcinaa01-ge020.denver.terabeam.net (216.137.17.21) 5.450 ms 6.128 ms 7.533 ms
  6 12.124.158.25 (12.124.158.25) 1.163 ms 1.572 ms 4.476 ms
  7 gbr1-p60.dvmco.ip.att.net (12.123.36.138) 2.529 ms 1.285 ms 6.739 ms
  8 gbr4-p70.dvmco.ip.att.net (12.122.5.21) 1.365 ms 3.114 ms 4.32 ms
  9 12.122.10.117 (12.122.10.117) 22.911 ms 19.350 ms 19.352 ms
10 tbr1-p012301.n54ny.ip.att.net (12.122.10.1) 38.500 ms 38.203 ms 44.327 ms
11 gar4-p300.n54ny.ip.att.net (12.123.3.2) 37.844 ms 37.614 ms 42.708 ms
12 12.126.124.82 (12.126.124.82) 39.463 ms 39.453 ms 39.360 ms
13 * * *
14 * * *
15 * * *
16 * * *
17 * * *
18 * * *
19 * * *
20 * * *
21 * * *
22 * * *
23 * * *
24 * * *
25 * * *
26 * * *
27 * * *
28 * * *
29 * * *
30 * * *

I've fiddled with our routes here, tried from different netblocks to no avail. Don't see any mention of bt at the puck.nether.net NOC list either. Thought about sending them mail, but wound up back at step #1 above...

2

Mike wrote:

We're receiving multiple complaints about problems reaching anything @bt. Is anyone else experiencing this?

Grrr....Three days later, BT is now telling their customers that somehow, this is our fault. I find it rather odd that everyone in the world can reach us, *except* BT customers, yet it is our fault.

NB, this only affects some of our address space (I received one confirmation report that another AS is also affected by this). I have tried four different peers, and it doesn't make a difference where I send outbound packets.

I have sent mail to every address @BT that looks like it might possess clue, to no avail. This is a general plea for help- if anyone has an idea of how I might resolve this, I would be very grateful...

From inside BT, looking at one of our clients colo'd servers:

C:\WINDOWS\Desktop>tracert www.indianmatches.com

Tracing route to www.indianmatches.com [204.144.133.198]
over a maximum of 30 hops:

   1 192 ms 110 ms 27 ms rase4nrp4.kingston.broadband.bt.net
[217.32.11.81]
   2 14 ms 14 ms 13 ms 217.41.195.2
   3 27 ms 14 ms 14 ms core1-pos4-1.kingston.ukcore.bt.net
[62.6.40.193]
   4 14 ms 13 ms 14 ms core1-pos5-1.ilford.ukcore.bt.net
[195.99.120.198]
   5 14 ms 14 ms 13 ms transit1-pos3-0.ilford.ukcore.bt.net
[194.72.20.226]
   6 96 ms 82 ms 82 ms transit2-pos7-0.newyork.ukcore.bt.net
[194.72.20.154]
   7 t2c2-ge6-2.us-nyb.concert.net [166.49.150.29] reports: Destination
host unreachable.

Trace complete

Well, no duh.... Going to www.concert.net I read "Concert, the AT&T and BT global communications venture, was legally closed on 1 April 2002".

Ok, so WTF are they sending packets for us that way then???

Mike

3

Mike wrote:

I have sent mail to every address @BT that looks like it might possess clue, to no avail. This is a general plea for help- if anyone has an idea of how I might resolve this, I would be very grateful...

On a hunch, I shut down one of our peering sessions which was passing our routes to AT&T. Suddenly things seem to be working again...

Thanks to all who've responded, I think we have a better idea of where the problem is now.

Mike

4

BT operate 2856 in the UK, and 5400 internationally

5400 used to be concert which was a BT/ATT venture which is now solely run by BT
under their brand - hence I guess why the msg on concert.net

Email contact sent offlist..

Steve

5

Point the customer at www.traceroute.org?

HTH,

Rich