Strange EIGRP/GRE issue !!

Discussion in 'Cisco' started by yepp, Jun 1, 2005.

  1. yepp

    yepp Guest

    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....
    yepp, Jun 1, 2005
    #1
    1. Advertising

  2. 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....
    >
    Helmut Ulrich, Jun 3, 2005
    #2
    1. Advertising

  3. yepp

    yepp Guest

    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.
    yepp, Jun 4, 2005
    #3
  4. yepp

    James Harris Guest

    "yepp" <> wrote in message
    news:...
    > 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.
    James Harris, Jun 25, 2005
    #4
  5. yepp

    shivlu

    Joined:
    Sep 13, 2006
    Messages:
    3
    I am facing the same issue

    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
    shivlu, Oct 7, 2009
    #5
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. steeda

    EIGRP through pix using GRE

    steeda, Oct 30, 2004, in forum: Cisco
    Replies:
    2
    Views:
    2,573
    Martin Bilgrav
    Nov 4, 2004
  2. Andrey Tarasov

    EIGRP, GRE and MTU

    Andrey Tarasov, Dec 18, 2004, in forum: Cisco
    Replies:
    3
    Views:
    3,721
    Andrey Tarasov
    Dec 28, 2004
  3. Replies:
    1
    Views:
    1,423
    Vincent C Jones
    Jul 6, 2005
  4. Replies:
    0
    Views:
    1,255
  5. Tosh

    Eigrp strange issue

    Tosh, Mar 19, 2006, in forum: Cisco
    Replies:
    9
    Views:
    4,654
Loading...

Share This Page