Have you got 'default-address-selection' configured on the router? This changes the default behaviour in terms of source address selection, which has helped me in similar cases. If you don't have it enabled, it might be worth trying it, if you do, it might be worth disabling it.
See: http://www.juniper.net/techpubs/software/junos/junos82/swconfig82-system -basics/html/sys-mgmt-misc4.html#1013962 Regards Michael -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Alasdair Lumsden Sent: 01 October 2007 03:09 To: [email protected] Subject: [j-nsp] Multipath per-packet load-balancing breaks ping tracerouteetc Hi All, I was wondering if anyone had experienced a similar problem I'm seeing with multipath, on a J2350, JunOS 8.4R2.3. The symptom is that when I enable multipath, tools on the router such as ping, traceroute, etc, cease to function (that is, to destinations via the multipath neighbours - pinging local IP addresses works). It isn't just limited to ping and traceroute, name resolution fails also. The router continues to route correctly, and the multipath works correctly (Both neighbour addresses appear in traceroutes through the router). Doing "show route DESTIP" displays the expected correct route, out via the correct interface - equipment using the router as their gateway can reach those destinations. It's just that tools on the router cannot. I can get around this by specifying a source interface or source IP to ping and traceroute; they then work as expected. Curiously, ping 255.255.255.255 works, with replies from both neighbour addresses, showing that it is selecting the correct interface even when you don't specify one. I'm fairly sure I haven't set anything out of the ordinary in my configuration. I have included snippets of the configuration below, plus examples of the symptoms. Full configuration can be provided if it would help. The problem isn't major, I can still SSH to the router, everything else works. It's just that it can't resolve hostnames, NTP won't work, and I can't ssh out. This isn't major, I could leave the router as is. However it bothers me - something isn't working correctly! Is this expected behaviour for multipath, or is it most likely a configuration problem? Could it potentially even be a bug in JunOS? Thanks in advance for any light people can shed! :) -- Alasdair ## Configuration snippets [EMAIL PROTECTED]> show configuration routing-options forwarding-table export equal_cost; [EMAIL PROTECTED]> show configuration policy-options policy-statement equal_cost from protocol bgp; then { load-balance per-packet; } [EMAIL PROTECTED]> show configuration protocols bgp damping; remove-private; group ProviderA { type external; local-address 195.72.129.158; import [ nobogons nosmallprefixes noprivateasns damping ]; export announce; peer-as XXX; multipath; neighbor 195.72.129.153; neighbor 195.72.129.154; } ## Example [EMAIL PROTECTED]> show route 64.233.169.147 inet.0: 229834 destinations, 538730 routes (227448 active, 0 holddown, 4795 hidden) Restart Complete + = Active Route, - = Last Active, * = Both 64.233.168.0/23 *[BGP/170] 03:10:21, localpref 100 AS path: 6908 3257 6453 15169 I > to 195.72.129.153 via ge-0/0/0.1051 to 195.72.129.154 via ge-0/0/0.1051 [BGP/170] 03:09:26, localpref 100 AS path: 6908 3257 1239 15169 I > to 195.72.129.154 via ge-0/0/0.1051 [EMAIL PROTECTED]> ping 64.233.169.147 PING 64.233.169.147 (64.233.169.147): 56 data bytes ^C --- 64.233.169.147 ping statistics --- 9 packets transmitted, 0 packets received, 100% packet loss [EMAIL PROTECTED]> ping 64.233.169.147 interface ge-0/0/0.1051 PING 64.233.169.147 (64.233.169.147): 56 data bytes 64 bytes from 64.233.169.147: icmp_seq=0 ttl=243 time=97.481 ms 64 bytes from 64.233.169.147: icmp_seq=1 ttl=243 time=90.375 ms 64 bytes from 64.233.169.147: icmp_seq=2 ttl=243 time=100.170 ms ^C --- 64.233.169.147 ping statistics --- 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max/stddev = 90.375/96.009/100.170/4.132 ms [EMAIL PROTECTED]> ping 64.233.169.147 source 195.72.129.158 PING 64.233.169.147 (64.233.169.147): 56 data bytes 64 bytes from 64.233.169.147: icmp_seq=0 ttl=243 time=104.552 ms 64 bytes from 64.233.169.147: icmp_seq=1 ttl=243 time=100.490 ms 64 bytes from 64.233.169.147: icmp_seq=2 ttl=243 time=90.414 ms ^C --- 64.233.169.147 ping statistics --- 3 packets transmitted, 3 packets received, 0% packet loss round-trip min/avg/max/stddev = 90.414/98.485/104.552/5.943 ms ## Traceroute issues [EMAIL PROTECTED]> traceroute 64.233.169.147 traceroute to 64.233.169.147 (64.233.169.147), 30 hops max, 40 byte packets 1 * * * 2 * * * ^C [EMAIL PROTECTED]> traceroute 64.233.169.147 source 195.72.129.158 no-resolve traceroute to 64.233.169.147 (64.233.169.147) from 195.72.129.158, 30 hops max, 40 byte packets 1 195.72.129.153 29.539 ms 9.453 ms 195.72.129.154 9.834 ms 2 213.200.77.153 9.621 ms 213.200.77.113 1.154 ms 17.957 ms 3 213.206.159.97 9.069 ms 9.377 ms 213.200.78.34 9.483 ms 4 195.219.195.1 9.086 ms 213.206.128.58 9.050 ms 9.284 ms MPLS Label=1505 CoS=0 TTL=1 S=1 5 195.219.195.6 9.176 ms 9.170 ms 213.206.128.54 9.517 ms 6 213.206.128.63 9.005 ms 195.219.67.206 9.266 ms 9.432 ms 7 82.195.189.186 9.200 ms 9.867 ms 209.85.252.40 19.056 ms 8 72.14.236.216 78.755 ms 209.85.252.40 9.539 ms 9.492 ms MPLS Label=303907 CoS=0 TTL=1 S=1 9 66.249.94.235 89.555 ms 72.14.232.95 9.275 ms 72.14.236.216 69.525 ms MPLS Label=303907 CoS=0 TTL=1 S=1 10 66.249.94.235 88.803 ms 209.85.251.89 99.647 ms 119.360 ms 11 64.233.175.109 89.155 ms 209.85.251.89 99.311 ms 72.14.232.21 99.560 ms 12 72.14.232.21 98.844 ms 119.387 ms 64.233.175.109 99.630 ms 13 64.233.169.147 88.913 ms 99.492 ms 89.696 ms ## Broadcast ping [EMAIL PROTECTED]> ping 255.255.255.255 PING 255.255.255.255 (255.255.255.255): 56 data bytes 64 bytes from 195.72.129.153: icmp_seq=0 ttl=255 time=7.807 ms 64 bytes from 195.72.129.154: icmp_seq=0 ttl=255 time=47.893 ms (DUP!) 64 bytes from 195.72.129.153: icmp_seq=1 ttl=255 time=10.394 ms 64 bytes from 195.72.129.154: icmp_seq=1 ttl=255 time=10.840 ms (DUP!) 64 bytes from 195.72.129.153: icmp_seq=2 ttl=255 time=10.390 ms 64 bytes from 195.72.129.154: icmp_seq=2 ttl=255 time=10.843 ms (DUP!) ^C --- 255.255.255.255 ping statistics --- 3 packets transmitted, 3 packets received, +3 duplicates, 0% packet loss round-trip min/avg/max/stddev = 7.807/16.361/47.893/14.140 ms [EMAIL PROTECTED]> ping 255.255.255.255 source 195.72.129.158 PING 255.255.255.255 (255.255.255.255): 56 data bytes 64 bytes from 195.72.129.153: icmp_seq=0 ttl=255 time=7.044 ms 64 bytes from 195.72.129.154: icmp_seq=0 ttl=255 time=7.562 ms (DUP!) 64 bytes from 195.72.129.153: icmp_seq=1 ttl=255 time=10.387 ms 64 bytes from 195.72.129.154: icmp_seq=1 ttl=255 time=10.839 ms (DUP!) 64 bytes from 195.72.129.153: icmp_seq=2 ttl=255 time=20.332 ms 64 bytes from 195.72.129.154: icmp_seq=2 ttl=255 time=20.863 ms (DUP!) ^C --- 255.255.255.255 ping statistics --- 3 packets transmitted, 3 packets received, +3 duplicates, 0% packet loss round-trip min/avg/max/stddev = 7.044/12.838/20.863/5.656 ## Traceroute through router root ~ (mail02): traceroute -n 64.233.169.147 traceroute to 64.233.169.147 (64.233.169.147), 30 hops max, 40 byte packets 1 91.194.74.92 0.201 ms 0.157 ms 0.153 ms 2 91.194.75.250 25.442 ms 30.063 ms 29.813 ms 3 195.72.129.154 0.945 ms 0.980 ms 195.72.129.153 11.857 ms 4 213.200.77.113 0.962 ms 213.200.77.153 1.025 ms 1.035 ms 5 213.200.78.34 1.279 ms 1.292 ms 213.206.159.97 1.294 ms 6 213.206.128.56 1.277 ms 195.219.195.1 1.607 ms 1.536 ms 7 213.206.129.151 0.991 ms 1.001 ms 195.219.195.6 1.023 ms 8 195.219.67.206 1.017 ms 213.206.128.63 121.856 ms 1.800 ms 9 209.85.252.40 1.262 ms 1.530 ms 82.195.189.186 1.278 ms 10 209.85.252.40 1.282 ms 72.14.236.216 100.409 ms 64.233.174.27 1.530 ms 11 72.14.236.216 108.084 ms 72.14.238.249 23.388 ms 66.249.94.235 77.392 ms 12 209.85.251.89 84.899 ms 66.249.94.235 77.201 ms 72.14.232.95 8.771 ms 13 72.14.232.21 80.229 ms 209.85.251.89 99.328 ms 72.14.232.21 79.014 ms 14 72.14.232.21 86.952 ms 80.038 ms 64.233.175.109 85.968 ms 15 64.233.169.147 77.425 ms 85.425 ms 77.182 ms _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
