Routing based on a ping of an upstream device

RO

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Nov 4, 2002, 1:19:05 PM11/4/02

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Hello,

I have two connections between myself and an extranet partner. We do
not run any type of routing protocol between these connections, and
are not allowed to. Even BGP is not an option. So far I have
configured with Static routes. However, static routes do not detect
if a router upstream from where I connect to my extranet partner goes
down. What I would like to do is make a static route that was
conditionally active if I was able to ping the interface of an
upstream device. IE My router pings a device on my partners network.
If the device responds back, a route stays in my routing table. If
there is no response, the route disappears until there is a response
again. Is this possible? Thanks!

Barry Margolin

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Nov 4, 2002, 1:51:32 PM11/4/02

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In article <664593ee.02110...@posting.google.com>,

You could run a script on a workstation on your LAN that does the ping
peridically. If it fails, it can use SNMP or a telnet script to update the
static route on the router.

--
Barry Margolin, bar...@genuity.net
Genuity, Woburn, MA
*** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
Please DON'T copy followups to me -- I'll assume it wasn't posted to the group.

D.Albertson

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Nov 4, 2002, 2:37:45 PM11/4/02

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How about a tunnel between you and your partners routers.

Then static route to to the far side tunnel address. If you cant get to the
far side the static routes will drop as the tunnel will go up/down.

"RO" <ro...@hotmail.com> wrote in message
news:664593ee.02110...@posting.google.com...

Wes

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Nov 5, 2002, 10:04:30 AM11/5/02

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ro...@hotmail.com (RO) wrote in message news:<664593ee.02110...@posting.google.com>...

> I have two connections between myself and an extranet partner. We do
> not run any type of routing protocol between these connections, and
> are not allowed to. Even BGP is not an option. So far I have
> configured with Static routes. However, static routes do not detect
> if a router upstream from where I connect to my extranet partner goes
> down.

Barry rightly points out that scripting on a server is your only way
to do this without routing protocols. That being said, routing
protocols are far more desirable.

Requirements should define Policy, Policy should not define
Requirements. Defining a Policy that you can not use routing
protocols, yet also defining a Requirement to detect upstream failures
and re-route is almost paradoxial; Policy and Requirements become
mutually-exclusive. Note I use the word "should". Sometimes no
matter how hard you try, you just can't convince the policy makers.

Good Luck! Remember, Policy changes quickly when the network goes
down for an extended period. <grin!>

--Wes

Aaron Leonard

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Nov 5, 2002, 12:35:28 PM11/5/02

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This will be doable with CSCds88143, "Add ICMP support for
PBR set next-hop verify availability" - not sure when that's
scheduled to be available though.

Aaron

---

~ Hello,
~
~ I have two connections between myself and an extranet partner. We do
~ not run any type of routing protocol between these connections, and
~ are not allowed to. Even BGP is not an option. So far I have
~ configured with Static routes. However, static routes do not detect
~ if a router upstream from where I connect to my extranet partner goes
~ down. What I would like to do is make a static route that was
~ conditionally active if I was able to ping the interface of an
~ upstream device. IE My router pings a device on my partners network.
~ If the device responds back, a route stays in my routing table. If
~ there is no response, the route disappears until there is a response
~ again. Is this possible? Thanks!