Subject: Please don't use 11.1-MFIB with DVMRP-mode tunnels

From: Bill Fenner <[email-masked]>
Date: Tue, 31 Mar 1998 13:35:48 PST

Folks,

  Please don't use the 11.1-MFIB branch with DVMRP-mode tunnels.  There is
a bug (which Cisco knows about and is working on) which can cause DVMRP-mode
tunnels to black hole all traffic flowing through them.  Route exchange
still works, so traffic gets routed through them; however forwarding is
broken and will black hole.

  Until Cisco has a fix available, please move your DVMRP-mode tunnels off
of your 11.1-MFIB routers, or run something other than 11.1-MFIB on them.
Otherwise, you can potentially cause black holes (this explains several of
the MBone's current problems).

Thanks,
  Bill

---

From: Steve Shultz <[email-masked]>
Date: Tue, 31 Mar 1998 23:57:50 -0800 (PST)

It is a common mistake to have "ip dvmrp unicast-routing" on dvmrp
tunnels. People should check their configs and remove dvmrp
unicast-routing on dvmrp tunnels.

interface tunnel 0
ip dvmrp unicast-routing
tunnel mode dvmrp

					Steve Shultz
					NASA Internet

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On Tue, 31 Mar 1998, Bill Fenner wrote:

> Date: Tue, 31 Mar 1998 13:35:48 PST
> From: Bill Fenner <[email-masked]>
> To: [email-masked], [email-masked]
> Cc: [email-masked]
> Subject: Please don't use 11.1-MFIB with DVMRP-mode tunnels
> 
> Folks,
>