Traceroute with multiple entries for one router

From: Richard Young (cc_young@xxxxxxxxxxx)
Date: Wed Sep 18 2002 - 21:01:33 GMT-3


   
I have a question about traceroute showing multiple hops for one router.

I am running Frame relay and the frame routers sometimes show multiple entries
to themselves. There does not appear to be a routing loop.

an example of the traceroute is shown below:
r3#trace 100.100.1.1

Type escape sequence to abort.
Tracing the route to 100.100.1.1

  1 133.10.34.4 16 msec 16 msec 16 msec
  2 133.10.24.2 20 msec 16 msec 16 msec
  3 133.10.25.5 36 msec 32 msec 32 msec
  4 133.10.25.5 32 msec 32 msec 36 msec
  5 133.10.156.1 56 msec 48 msec 48 msec
  6 133.10.156.1 48 msec 48 msec 48 msec
  7 133.10.23.6 56 msec 56 msec 56 msec
  8 133.10.68.8 60 msec 56 msec 56 msec
  9 133.10.81.11 72 msec * 68 msec
Notice hops 3 and 4 are to the same device as well as hops 5 and 6.
host 133.10.25.5 is the hub in a hub and spoke frame relay, and 133.10.156.1 is
one of the spokes.

There does not appear to be any problems with the routing that I can see.
Route tables are shown below.
r2#sh ip route

Gateway of last resort is not set

     100.0.0.0/24 is subnetted, 1 subnets
B 100.100.1.0 [200/0] via 133.10.1.1, 00:55:48
D EX 192.168.5.0/24 [170/2611200] via 133.10.24.4, 01:36:15, Ethernet0
     133.10.0.0/16 is variably subnetted, 16 subnets, 2 masks
D EX 133.10.156.0/24 [170/3097600] via 133.10.25.5, 01:33:27, Serial0
D EX 133.10.11.0/24 [170/3097600] via 133.10.25.5, 01:30:32, Serial0
D EX 133.10.10.0/24 [170/3097600] via 133.10.25.5, 01:31:45, Serial0
D EX 133.10.8.0/24 [170/3097600] via 133.10.25.5, 01:31:45, Serial0
D EX 133.10.6.0/24 [170/3097600] via 133.10.25.5, 01:31:46, Serial0
D EX 133.10.5.0/24 [170/3097600] via 133.10.25.5, 01:33:28, Serial0
D EX 133.10.3.0/24 [170/2611200] via 133.10.24.4, 01:36:16, Ethernet0
C 133.10.2.0/24 is directly connected, Loopback0
D EX 133.10.1.0/24 [170/3097600] via 133.10.25.5, 01:31:46, Serial0
C 133.10.25.0/24 is directly connected, Serial0
C 133.10.24.0/25 is directly connected, Ethernet0
D EX 133.10.23.0/24 [170/3097600] via 133.10.25.5, 01:31:47, Serial0
D EX 133.10.34.0/24 [170/2611200] via 133.10.24.4, 01:36:18, Ethernet0
D EX 133.10.56.0/24 [170/3097600] via 133.10.25.5, 01:31:47, Serial0
D EX 133.10.68.0/24 [170/3097600] via 133.10.25.5, 01:31:47, Serial0
D EX 133.10.81.0/24 [170/3097600] via 133.10.25.5, 01:30:39, Serial0
D EX 192.168.1.0/24 [170/2611200] via 133.10.24.4, 01:36:18, Ethernet0
D EX 192.168.3.0/24 [170/2611200] via 133.10.24.4, 01:36:18, Ethernet0
r2#

r5#sh ip route

Gateway of last resort is not set

     100.0.0.0/24 is subnetted, 1 subnets
B 100.100.1.0 [200/0] via 133.10.1.1, 00:56:08
D EX 192.168.5.0/24 [170/3123200] via 133.10.25.2, 01:33:43, Serial0.1
C 192.168.0.0/24 is directly connected, Ethernet0
     133.10.0.0/16 is variably subnetted, 16 subnets, 2 masks
C 133.10.156.0/24 is directly connected, Serial0.2
O IA 133.10.11.0/24 [110/193] via 133.10.156.6, 01:30:53, Serial0.2
O IA 133.10.10.0/24 [110/75] via 133.10.156.1, 01:31:55, Serial0.2
                       [110/75] via 133.10.156.6, 01:31:56, Serial0.2
O IA 133.10.8.0/24 [110/129] via 133.10.156.6, 01:31:56, Serial0.2
O 133.10.6.0/24 [110/65] via 133.10.156.6, 01:31:56, Serial0.2
C 133.10.5.0/24 is directly connected, Loopback0
D EX 133.10.3.0/24 [170/3123200] via 133.10.25.2, 01:33:44, Serial0.1
D 133.10.2.0/24 [90/2297856] via 133.10.25.2, 01:33:45, Serial0.1
O 133.10.1.0/24 [110/65] via 133.10.156.1, 01:31:58, Serial0.2
C 133.10.25.0/24 is directly connected, Serial0.1
D 133.10.24.0/25 [90/2195456] via 133.10.25.2, 01:33:45, Serial0.1
O IA 133.10.23.0/24 [110/74] via 133.10.156.1, 01:31:58, Serial0.2
                       [110/74] via 133.10.156.6, 01:31:58, Serial0.2
D EX 133.10.34.0/24 [170/3123200] via 133.10.25.2, 01:33:46, Serial0.1
O 133.10.56.0/24 [110/1626] via 133.10.156.6, 01:31:58, Serial0.2
O IA 133.10.68.0/24 [110/128] via 133.10.156.6, 01:31:58, Serial0.2
O IA 133.10.81.0/24 [110/192] via 133.10.156.6, 01:31:00, Serial0.2
D EX 192.168.1.0/24 [170/3123200] via 133.10.25.2, 01:33:46, Serial0.1
D EX 192.168.3.0/24 [170/3123200] via 133.10.25.2, 01:33:46, Serial0.1
r5#
r

r1#sh ip route

Gateway of last resort is not set

     100.0.0.0/24 is subnetted, 1 subnets
B 100.100.1.0 [200/0] via 133.10.68.8, 00:56:20
O E2 192.168.5.0/24 [110/50] via 133.10.156.5, 01:31:57, Serial0
     133.10.0.0/16 is variably subnetted, 17 subnets, 3 masks
C 133.10.156.0/24 is directly connected, Serial0
O IA 133.10.11.0/24 [110/139] via 133.10.23.6, 01:31:05, Ethernet0
O 133.10.10.0/24 [110/11] via 133.10.23.11, 01:35:46, Ethernet0
O IA 133.10.8.0/24 [110/75] via 133.10.23.6, 01:32:07, Ethernet0
O 133.10.6.0/24 [110/11] via 133.10.23.6, 01:32:08, Ethernet0
O 133.10.5.0/24 [110/65] via 133.10.156.5, 01:32:08, Serial0
O E2 133.10.3.0/24 [110/50] via 133.10.156.5, 01:31:58, Serial0
O E2 133.10.2.0/24 [110/50] via 133.10.156.5, 01:31:58, Serial0
C 133.10.1.0/24 is directly connected, Loopback0
O E2 133.10.25.0/24 [110/50] via 133.10.156.5, 01:32:00, Serial0
O E2 133.10.24.0/25 [110/50] via 133.10.156.5, 01:32:00, Serial0
O 133.10.23.0/24 is a summary, 01:35:48, Null0
C 133.10.23.0/26 is directly connected, Ethernet0
O E2 133.10.34.0/24 [110/50] via 133.10.156.5, 01:32:00, Serial0
O 133.10.56.0/24 [110/1572] via 133.10.23.6, 01:32:10, Ethernet0
O IA 133.10.68.0/24 [110/74] via 133.10.23.6, 01:32:10, Ethernet0
O IA 133.10.81.0/24 [110/138] via 133.10.23.6, 01:31:12, Ethernet0
O E2 192.168.1.0/24 [110/50] via 133.10.156.5, 01:32:00, Serial0
O E2 192.168.3.0/24 [110/50] via 133.10.156.5, 01:32:00, Serial0
r1#
r1#
r1#

Any Ideas?



This archive was generated by hypermail 2.1.4 : Sat Sep 07 2002 - 19:48:28 GMT-3