"[EMAIL PROTECTED] (Timothy Ouellette)" wrote:
> From what I see it, it looks like per destination load balancing where
> I thought with no ip route-cache turned ont hat it would be per packet
> load balancing? I think I figured it out last night but from the
> initial setup I thought i'd see one ping go over s0 and the next for
> s1 and so on.
>
> TIm
Hi Tim,
I blew the dust off my little router lab early this evening and tried it
myself. It
seems to be an IOS version problem. I was able to reproduce your result of
undesired
per-destination load balancing with "no ip-route cache" on version 11.2. But
when I
upgraded to 12.0(9) the per packet load balancing works okay. See my results
below.
-Jonathan
=====
The command "show ip cache" is not necessarily a good indicator of whether
fast
switching is enabled. The "sh ip interface" command is better. See the
before and after
snippets below and you will notice no change in the "sh ip cache" output.
=====
rB-2514#sh ip int s0
Serial0 is up, line protocol is up
Internet address is 10.1.2.2/30
[snip]
IP fast switching is enabled
[snip]
rB-2514#sh ip cache
IP routing cache 0 entries, 0 bytes
0 adds, 0 invalidates, 0 refcounts
Minimum invalidation interval 2 seconds, maximum interval 5 seconds,
quiet interval 3 seconds, threshold 0 requests
Invalidation rate 0 in last second, 0 in last 3 seconds
Prefix/Length Age Interface Next Hop
=====
rB-2514#conf t
Enter configuration commands, one per line. End with CNTL/Z.
rB-2514(config)#int s0
rB-2514(config-if)#no ip route-cache
rB-2514(config-if)#end
rB-2514#
rB-2514#sh ip int s0
Serial0 is up, line protocol is up
Internet address is 10.1.2.2/30
[snip]
IP fast switching is disabled
[snip]
rB-2514#sh ip cache
IP routing cache 0 entries, 0 bytes
0 adds, 0 invalidates, 0 refcounts
Minimum invalidation interval 2 seconds, maximum interval 5 seconds,
quiet interval 3 seconds, threshold 0 requests
Invalidation rate 0 in last second, 0 in last 3 seconds
Prefix/Length Age Interface Next Hop
rB-2514#
=====
Next, here is my reproduction of your configuration, with "debug ip icmp".
First, with IOS 11.2:
=====
rA-2511#sh ip route
[snip]
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 5 subnets, 2 masks
C 10.1.3.0/24 is directly connected, Loopback1
C 10.1.2.0/30 is directly connected, Serial0
R 10.0.0.0/24 [120/1] via 10.1.2.1, 00:00:05, Serial0
[120/1] via 10.1.4.1, 00:00:05, Serial1
R 10.1.1.0/24 [120/1] via 10.1.4.1, 00:00:05, Serial1
[120/1] via 10.1.2.1, 00:00:05, Serial0
C 10.1.4.0/30 is directly connected, Serial1
25.0.0.0/24 is subnetted, 1 subnets
C 25.25.25.0 is directly connected, Loopback0
rA-2511#sh ver
Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-JS-L), Version 11.2(16), RELEASE SOFTWARE (fc1)
[snip]
rA-2511#ping 10.1.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 32/35/36 ms
rA-2511#
ICMP: echo reply rcvd, src 10.1.1.1, dst 10.1.2.2
ICMP: echo reply rcvd, src 10.1.1.1, dst 10.1.2.2
ICMP: echo reply rcvd, src 10.1.1.1, dst 10.1.2.2
ICMP: echo reply rcvd, src 10.1.1.1, dst 10.1.2.2
ICMP: echo reply rcvd, src 10.1.1.1, dst 10.1.2.2
=====
And then next time I ping it uses 10.1.4.2, just as you showed in your post.
So I flashed the router to IOS version 12.0(9), making no changes whatsoever
to the
configuration. Here is the result:
=====
rA-2511#sh ver
Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-IO-L), Version 12.0(9), RELEASE SOFTWARE (fc1)
[snip]
rA-2511#ping 10.1.1.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 40/68/112 ms
rA-2511#
00:02:26: ICMP: echo reply rcvd, src 10.1.1.1, dst 10.1.2.2
00:02:26: ICMP: echo reply rcvd, src 10.1.1.1, dst 10.1.4.2
00:02:26: ICMP: echo reply rcvd, src 10.1.1.1, dst 10.1.2.2
00:02:26: ICMP: echo reply rcvd, src 10.1.1.1, dst 10.1.4.2
00:02:26: ICMP: echo reply rcvd, src 10.1.1.1, dst 10.1.2.2
rA-2511#
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