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DECnet over GRE tunnel with FiberOptic leased-line

Hi All,

I have a problem in tunneling DECNET traffic over GRE using FiberOptic leased-line as the media in the middle of the network.

DECNET terminal - router - layer3 switch - FiberOptic - layer3 switch - router - DECNET server

Although the DECNET packet is smaller the link mtu, I guess, I've try to enable tunnel PMTUD (tunnel path-mtu-discovery) and configure ip mtu

1476 in the tunnel interface.

Then I tried to modify the DF-bit using ip policy route-map in the tunnel interface. It still doesn't work.

Has anyone ever experience this problem?

Does it have something to do with the GRE Tunnel latency?

Regards, Sali

Reply to
sali
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Is IP working over the GRE tunnel ?

Does CDP flow over the tunnel ?

Post a sanitized configs of both routers and the post the output from both routers for

  1. sh version

  1. sh decnet

  2. sh decnet interface

  1. sh decnet route

  2. sh decnet nei

Are Decnet hellos being exchanged over the tunnel ?

debug decnet adj

Reply to
Merv

Do you have "decnet cost x" configured on tunnel interfaces ?

Reply to
Merv

This wouldn't be LAT would it? That won't work (LAT) without configuring bridging on the tunnel. In the later IOS releases bridging isn't supported (but can be configured) on the GRE tunnel interface.

Reply to
Neil Cherry

If it is LAT, then LAT to TCP protocol translation should be used

see Cisco doc

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Reply to
Merv

formatting link

The only problem with that is it very resource intensive (memory and CPU) and it doesn't support LAST and LAVC (sp?). It does work very well.

Reply to
Neil Cherry

Well if the OP is trying to run vax cluster traffic over the Internet then all bets are off ...

Reply to
Merv

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