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Strange EIGRP/GRE issue !!

 
 
yepp
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Posts: n/a
 
      06-01-2005
Hi,

My site has two routers on same public segment, share the same internet
link. These 2 routers are part of the corporate vpn network and it's
running gre tunnel, EIGRP is the routing protocol, both routers already
installed vpn acclerator to enhance performance.

Internet
|
router A (F0/0) ---- Switch ---- router B (F0/0)
| |
LAN A LAN B

On these two routers, I've create a direct tunnel between them. When I
do a ping test from router A external to router B external, the latency
is less than 10ms cos they're under same public segment. However, when
I do a ping test from router A to router B via gre tunnel, the latency
is > 250ms. It's quite unresanable & unacceptable. Could anyone give me
a clue why the gre tunnel performance is so bad while two routers are
on same network ? Is there any parameter I missed?

Router A
Tunnel 1
ip address unnumbered L0
tunnel source interface F0/0
bandwidth 64
delay 1700
ip eigrp 0 30
tunnel destination address 200.200.200.2

Router B
Tunnel 1
ip address unnumbered L0
tunnel source interface F0/0
bandwidth 64
delay 1700
ip eigrp 0 30
tunnel destination address 200.200.200.1

Thanks....

 
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Helmut Ulrich
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Posts: n/a
 
      06-03-2005
The whole configuration of both routers would be helpful.

yepp schrieb:
> Hi,
>
> My site has two routers on same public segment, share the same internet
> link. These 2 routers are part of the corporate vpn network and it's
> running gre tunnel, EIGRP is the routing protocol, both routers already
> installed vpn acclerator to enhance performance.
>
> Internet
> |
> router A (F0/0) ---- Switch ---- router B (F0/0)
> | |
> LAN A LAN B
>
> On these two routers, I've create a direct tunnel between them. When I
> do a ping test from router A external to router B external, the latency
> is less than 10ms cos they're under same public segment. However, when
> I do a ping test from router A to router B via gre tunnel, the latency
> is > 250ms. It's quite unresanable & unacceptable. Could anyone give me
> a clue why the gre tunnel performance is so bad while two routers are
> on same network ? Is there any parameter I missed?
>
> Router A
> Tunnel 1
> ip address unnumbered L0
> tunnel source interface F0/0
> bandwidth 64
> delay 1700
> ip eigrp 0 30
> tunnel destination address 200.200.200.2
>
> Router B
> Tunnel 1
> ip address unnumbered L0
> tunnel source interface F0/0
> bandwidth 64
> delay 1700
> ip eigrp 0 30
> tunnel destination address 200.200.200.1
>
> Thanks....
>


 
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yepp
Guest
Posts: n/a
 
      06-04-2005
I'll get the router config and post it later. One other question: For a
Cisco1721 w/vpn accelerator, if this configure 10 gre tunnels, is this
router powerful enough ? will it cause any performance issue ? I raise
up this issue cos I found that all the gre tunnels on this router are
having latency issue.....

Pls advise.

 
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James Harris
Guest
Posts: n/a
 
      06-25-2005

"yepp" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) oups.com...
> Hi,
>
> My site has two routers on same public segment, share the same
> internet
> link. These 2 routers are part of the corporate vpn network and it's
> running gre tunnel, EIGRP is the routing protocol, both routers
> already
> installed vpn acclerator to enhance performance.
>
> Internet
> |
> router A (F0/0) ---- Switch ---- router B (F0/0)
> | |
> LAN A LAN B
>
> On these two routers, I've create a direct tunnel between them. When I
> do a ping test from router A external to router B external, the
> latency
> is less than 10ms cos they're under same public segment. However, when
> I do a ping test from router A to router B via gre tunnel, the latency
> is > 250ms. It's quite unresanable & unacceptable. Could anyone give
> me
> a clue why the gre tunnel performance is so bad while two routers are
> on same network ? Is there any parameter I missed?


I'd suggest taking the hops one by one - send and return - and checking
the routing table in each case. Remember that the tunnel will need two
lookups - one pointing the router at the tunnel remote end and the other
pointing the router itself at the tunnel endpoint once the packet has
been encapsulated. Also the return journey will depend on the source
address in each case. May be an asymmetry.


 
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shivlu shivlu is offline
Junior Member
Join Date: Sep 2006
Posts: 3
 
      10-07-2009
I am almost facing the same issue. Please check my post. The problem is that the tunnel destination ip address is working fine but the tunnel ip address is facing latency and drops. I am suspecting the problem because of the asymmetric load balancing in the path because of CEF. CEF uses destination based by defauly by changing per packet based solved my issue. But don't have any option to check the issue. For more please visit my blog and also add the comments.

regards
shivlu jain
shivlu dot blogspot dot com
 
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