Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Strange EIGRP/GRE issue

I have 2 3825 routers and have configured GRE+ EIGRP. I have 2 tunnels one going to loctnA and the other to loctnB. The GRE tunnel to loctnA is pefect. There is a lot of latency on the loctnB GRE tunnel. The end to end ping to the physical interace results in a avg latency of 4 msec, whereas ping to the tunnel interface reseults on 110 msec.

Any leads?

-Sai.

5 REPLIES

Re: Strange EIGRP/GRE issue

HI Sai, [Pls Rate if HELPS]

What is the "Tunnel Mode" configured on the Tunnel Interface.

If Tunnel Mode as "ipip" is configured means, remove the same and try. I have experienced the smiliar issue and after doing a same it worked properly.

Also, redo the configuration of EIGRP on either side for Location B. This will something look like a propability try but have experienced several such cases with EIGRP and after redo of config it has worked.

Pls Rate if HELPS

Best Regards,

Guru Prasad R

New Member

Re: Strange EIGRP/GRE issue

Hi Guru,

everyting is default there is no ipip configured.

Hall of Fame Super Bronze

Re: Strange EIGRP/GRE issue

Please post the relevant portion of the config.

__

Edison.

New Member

Re: Strange EIGRP/GRE issue

Tunnel1 is having the issue.

interface Tunnel0

bandwidth 6000

ip address 10.254.82.70 255.255.255.252

ip mtu 1420

ip tcp adjust-mss 1380

load-interval 30

delay 1

keepalive 10 3

tunnel source 10.254.82.126

tunnel destination 10.254.82.66

!

interface Tunnel1

bandwidth 6000

ip address 10.254.83.1 255.255.255.252

ip tcp adjust-mss 1380

load-interval 30

delay 1

qos pre-classify

keepalive 10 3

tunnel source 10.254.82.58

tunnel destination 10.254.82.57

!

!

interface FastEthernet1/0

ip address 10.254.82.126 255.255.255.252

no ip redirects

no ip unreachables

no ip proxy-arp

ip accounting output-packets

ip flow ingress

ip flow egress

ip route-cache flow

no ip mroute-cache

load-interval 30

duplex full

speed 100

no cdp enable

!

interface FastEthernet1/1

bandwidth 6000

ip address 10.254.82.58 255.255.255.252

no ip redirects

no ip unreachables

no ip proxy-arp

no ip mroute-cache

delay 1

duplex full

speed 100

no cdp enable

!

router eigrp

redistribute static

network 10.30.1.0 0.0.0.255

network 10.254.82.60 0.0.0.3

network 10.254.82.68 0.0.0.3

network 10.254.83.0 0.0.0.3

no auto-summary

!

router bgp

no synchronization

bgp log-neighbor-changes

neighbor 10.254.82.125 remote-as

no auto-summary

!

ip classless

ip route 10.30.0.0 255.255.0.0 10.30.1.254

ip route 10.108.32.0 255.255.240.0 10.30.1.254

ip route 10.254.32.176 255.255.255.240 10.30.1.254

ip route 172.21.167.0 255.255.255.0 10.30.1.254

New Member

Re: Strange EIGRP/GRE issue

MTU mismatch may cause the issue since it will cause many more traffic fragmentations.

I saw you have "ip mtu 1420" setup in Tunnel0 why not in Tunnel1? Any history reason?

I would suggest to configure same in Tunnel1 and give it try.

Or, use 'tunnel path-mtu-discovery' in Tunnel1 for its to do automatically detect proper MTU for end-2-end trffic flow.

Please let me know the result and rate it.

178
Views
0
Helpful
5
Replies