Comment 8 for bug 556831

If there isn't a good way to be able to gracefully work from this scenario (in the past I think the timeouts were just a lot lower), then it would be preferable to support an optional preseed template to tell it to not try to verify any sources written to sources.list.

From a machine on the same network as this occurs:

$ tracepath archive.ubuntu.com -n
 1: 10.9.160.254 0.153ms pmtu 1500
 1: 10.9.160.1 0.736ms
 2: 10.9.29.2 0.601ms
 3: 10.254.251.246 asymm 2 0.738ms
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     Too many hops: pmtu 1500
     Resume: pmtu 1500
$ ping archive.ubuntu.com
PING archive.ubuntu.com (91.189.88.30) 56(84) bytes of data.

--- archive.ubuntu.com ping statistics ---
6 packets transmitted, 0 received, 100% packet loss, time 5009ms

$ /sbin/route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.9.160.0 0.0.0.0 255.255.248.0 U 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0
0.0.0.0 10.9.160.1 0.0.0.0 UG 0 0 0 eth0