eigrp redistribute question

henrybb · ‎04-22-2003

My network is 3640,7500 and four 6509 msfc interconnected with ethernet vlan 200,like this:

6509 msfc(10.1.200.250)----vlan 200----3640(10.1.200.246)

6509 msfc(10.1.200.251)----vlan 200----7500(10.1.200.248)

6509 msfc(10.1.200.252)----vlan 200

6509 msfc(10.1.200.254)----vlan 200

I have a eigrp's problem.Two external route are changed frequently on cisco router 7500.The two external router

is redistributed on 6509 msfc,and it stays long on 3640.When I show ip eigrp events on one of four msfcs,I can

see "14:16:32.177 Poison squashed: 10.88.254.1/32 reverse" and " 14:16:32.177 Poison squashed: 0.0.0.0/0

reverse".I think maybe it is the reason.But I am in doubt why 3640 is work ok. Can anybody point me how to

troubleshooting this? When and why 6509 msfc "Poison squashed: 10.88.254.1/32 reverse" ? Why 7500's routing table

is changed and 3640 is not?

thanks !

any comment is appreciated!

3640#sh ip route

D EX 10.88.254.1/32 [170/281600] via 10.1.200.254, 1d05h, Ethernet0/0

[170/281600] via 10.1.200.251, 1d05h, Ethernet0/0

[170/281600] via 10.1.200.250, 1d05h, Ethernet0/0

[170/281600] via 10.1.200.252, 1d05h, Ethernet0/0

D*EX 0.0.0.0/0 [170/281600] via 10.1.200.254, 1d05h, Ethernet0/0

[170/281600] via 10.1.200.251, 1d05h, Ethernet0/0

[170/281600] via 10.1.200.250, 1d05h, Ethernet0/0

[170/281600] via 10.1.200.252, 1d05h, Ethernet0/0

3640>sh ip eigrp nei

IP-EIGRP neighbors for process 1

H Address Interface Hold Uptime SRTT RTO Q Seq

(sec) (ms) Cnt Num

0 10.1.200.248 Et0/0 13 1w2d 20 450 0 282759

9 10.1.200.252 Et0/0 11 1w2d 16 450 0 10937

8 10.1.200.254 Et0/0 14 1w2d 17 450 0 10932

4 10.1.200.250 Et0/0 12 1w2d 17 450 0 10988

2 10.1.200.251 Et0/0 14 1w2d 19 450 0 10987

7500#sh ip route

D EX 10.88.254.1/32

[170/28160] via 10.1.200.252, 01:13:07, FastEthernet1/1/0

[170/28160] via 10.1.200.250, 01:13:07, FastEthernet1/1/0

[170/28160] via 10.1.200.254, 01:13:07, FastEthernet1/1/0

[170/28160] via 10.1.200.251, 01:13:07, FastEthernet1/1/0

D*EX 0.0.0.0/0 [170/28160] via 10.1.200.252, 01:13:18, FastEthernet1/1/0

[170/28160] via 10.1.200.250, 01:13:18, FastEthernet1/1/0

[170/28160] via 10.1.200.254, 01:13:18, FastEthernet1/1/0

[170/28160] via 10.1.200.251, 01:13:18, FastEthernet1/1/0

7500#sh ip eigrp nei

IP-EIGRP neighbors for process 1

H Address Interface Hold Uptime SRTT RTO Q Seq Type

(sec) (ms) Cnt Num

31 10.1.200.251 Fa1/1/0 13 1w2d 1 300 0 10991

29 10.1.200.250 Fa1/1/0 11 1w2d 1 300 0 10992

28 10.1.200.254 Fa1/1/0 13 1w2d 1 300 0 10936

27 10.1.200.252 Fa1/1/0 14 1w2d 1 300 0 10941

25 10.1.200.246 Fa1/1/0 12 1w2d 1 300 0 34149

6509_1#sh ip route

S 10.88.254.1/32 [1/0] via 10.0.8.3

S* 0.0.0.0/0 [1/0] via 10.1.100.248

6509_1>sh ip eigrp nei

IP-EIGRP neighbors for process 1

H Address Interface Hold Uptime SRTT RTO Q Seq Type

(sec) (ms) Cnt Num

5 10.1.200.248 Vl200 11 1w2d 44 594 0 282759

1 10.1.200.246 Vl200 13 1w2d 11 450 0 34145

8 10.1.200.252 Vl200 13 1w2d 8 1012 0 10937

7 10.1.200.254 Vl200 12 1w2d 25 1012 0 10932

9 10.1.200.251 Vl200 13 1w2d 8 1012 0 10937

6509_1>sh ip eigrp events

Event information for AS 18:

1 14:16:32.257 Poison squashed: 10.76.0.0/14 reverse

2 14:16:32.241 Change queue emptied, entries: 1

3 14:16:32.241 Metric set: 10.76.0.0/14 1807360

4 14:16:32.241 Update reason, delay: metric chg 517120

5 14:16:32.241 Update sent, RD: 10.76.0.0/14 1807872

6 14:16:32.241 Route install: 10.76.0.0/14 10.1.200.248

7 14:16:32.241 Route install: 10.76.0.0/14 10.1.200.245

8 14:16:32.241 FC sat rdbmet/succmet: 1807360 1804800

9 14:16:32.241 FC sat nh/ndbmet: 10.1.200.248 1807872

10 14:16:32.241 Find FS: 10.76.0.0/14 1807360

11 14:16:32.241 Rcv update met/succmet: 1807360 1804800

12 14:16:32.241 Rcv update dest/nh: 10.76.0.0/14 10.1.200.248

13 14:16:32.177 Poison squashed: 10.88.254.1/32 reverse

14 14:16:32.177 Poison squashed: 0.0.0.0/0 reverse

15 14:16:32.177 Poison squashed: 10.0.224.0/19 reverse

16 14:16:27.329 Poison squashed: 10.76.0.0/14 reverse

17 14:16:27.225 RDB delete: 10.76.0.0/14 10.1.200.248

18 14:16:27.201 Poison squashed: 10.76.0.0/14 reverse

19 14:16:27.173 Change queue emptied, entries: 1

20 14:16:27.173 Metric set: 10.76.0.0/14 1807872

21 14:16:27.173 Update reason, delay: metric chg 517120

22 14:16:27.173 Update sent, RD: 10.76.0.0/14 1807360

23 14:16:27.173 Route install: 10.76.0.0/14 10.1.200.245

24 14:16:27.173 Send reply: 10.76.0.0/14 10.1.200.248

25 14:16:27.173 FC sat rdbmet/succmet: 1807872 1805312

26 14:16:27.173 FC sat nh/ndbmet: 10.1.200.245 1807360

27 14:16:27.173 Find FS: 10.76.0.0/14 1807360

28 14:16:27.173 Rcv query met/succ met: 4294967295 4294967295

29 14:16:27.173 Rcv query dest/nh: 10.76.0.0/14 10.1.200.248

jbayuka · ‎04-28-2003

The "poison squashed" indicates that the remote router is doing split-horizon with poisoned reverse, which is by default turned on in EIGRP.

The message means that the router is getting a routing update from its neighbor with an unreachable(a poison) metric, about which this MSFC doesnt anything about, and thus we will discard it(squash) without processing it.

I am not sure how this event would affect 7500

henrybb · ‎04-28-2003

I investigate this for these two days.Maybe I found the reason.MY topu is actually like this:

6509 msfc(10.1.200.250)-vlan 200-3640(10.1.200.246)-wan 1--r1

6509 msfc(10.1.200.251)-vlan 200-7500(10.1.200.248)-wan 2--r1

6509 msfc(10.1.200.252)-vlan 200

6509 msfc(10.1.200.254)-vlan 200

I think the flowchart is like this:

1. wan 2 is down

2. wan 2 is up

3. r1 will build eigrp neighbor with 7500,and send update to 7500.

4. 7500 receive update and begin DUAL.because r1 is not successor of 7500 except 10.76.0.0(suppose this),so DUAL is local-compution,and 7500 will not send update to other except 10.76.0.0.

5. 7500 will reset sh ip route timeclock,so when I show ip route,all route 's uptime will change frequently because my wan is not stablity.And I show ip eigrp nei,I found there is one neighbor's uptime is same as sh ip route uptime.

So I think this is the reason.and I found this on routing tcp/ip vol 1 p 207:

A router will reassess its list of feasible successors for a route, as described in the last section, any time an

input event occurs. An input event can be:

A change in the cost of a directly connected link

A change in the state (up or down) of a directly connected link

The reception of an update packet---->this is the reason?

The reception of a query packet

The reception of a reply packet

English is not my native language,so I can't express exactly what I think.

Hope you can understand .

thanks!