From: CCIE FUN (ccieexam2002@yahoo.com)
Date: Sat Feb 22 2003 - 00:08:18 GMT-3
Item # 2 is true but there is workaround.
You can configure a GRE tunnel across the stub area to
skirt around the issue of virtual link.
The GRE tunnel will give you same functionality as the
Virtual-link, i.e. link a non-zero area to the area 0
over the GR tunnel via the sutb area.
--- P729 <p729@cox.net> wrote:
> "3. If you set a p2p link as ip ospf
> point-to-multipoint then what you will
> see
> is /32's being advertised for both your end points
> of the link breaking the
> split horizon rule. I am not sure why the /32 sets
> sent."
>
> Um...OSPF, being a link-state protocol, doesn't use
> split-horizon...and the
> /32's aren't really "sent," but installed by the
> OSPF process in the routers
> themselves after the adjacencies form so that the
> underlying
> point-to-multipoint fabric looks like a set of
> pseudo point-to-point links.
>
> Here's one for you:
>
http://www.cisco.com/cgi-bin/Support/Bugtool/onebug.pl?bugid=CSCdu34902&Subm
> it=Search
>
> "OSPF may send external LSAs with zero forwarding
> address instead of
> non-zero forwarding address. This is a configuration
> issue and can happen if
> complete interface address and zero mask is
> specified in network command
> under "router ospf".
>
> Workaround is to specify subnet address and mask in
> the network command."
>
> Regards,
>
> Mas Kato
> https://ecardfile.com/id/mkato
>
> ----- Original Message -----
> From: <ray_gan74@hotmail.com>
> To: <ccielab@groupstudy.com>
> Sent: Thursday, February 20, 2003 12:10 PM
> Subject: CCIE Gotchas: Watch out!
>
>
> Wanted to start a thread on some gotchas to look out
> for when configuring
> protocols/redistribution. PLEASE contribute. Ill go
> first.
>
> 1. BGP-->OSPF redistribution
>
> What = Routes not advertised to ibgp peers.
> Why? = Router ID's of ospf and bgp don't match.
> Solution: Use BGP confederations which does not
> suffer from this issue.
> Use another IGP instead of OSPF. Turn off BGP
> synchronization on each BGP
> router within AS. Hardcode the OSPF
> and BGP router-id's to so
> that they match.
>
>
> 2. You can not configure a virtual link across a
> stub area
>
>
> 3. If you set a p2p link as ip ospf
> point-to-multipoint then what you will
> see
> is /32's being advertised for both your end points
> of the link breaking the
> split horizon rule. I am not sure why the /32 sets
> sent.
>
> .
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