«

I would like to have a redundant link to a building.
I'm thinking of having one link via radio and another one via a VPN lan2lan
tunnel.
This will be the cheapest wan solution.
But I can't figure out how to solve the redundacy part of it.

EIGRP is rp that i use. But how will the router detect that one link is
down?
I will not get any physical link down from the tunnel or the radio equipment
when the link is down.
Any suggestions?

TIA
Bengt

"Bengt Ohlen" <> wrote in message
news:gb4qb.2013$...
> I would like to have a redundant link to a building.
> I'm thinking of having one link via radio and another one via a VPN
lan2lan
> tunnel.
> This will be the cheapest wan solution.
> But I can't figure out how to solve the redundacy part of it.
>
> EIGRP is rp that i use. But how will the router detect that one link is
> down?
> I will not get any physical link down from the tunnel or the radio
equipment
> when the link is down.
> Any suggestions?
>

There are some good papers about redundacy on www.networkingunlimited.com

Ivan

In article <boann9$1cg8tr$>,
Ivan Ostres <> wrote:
>"Bengt Ohlen" <> wrote in message
>news:gb4qb.2013$...
>> I would like to have a redundant link to a building.
>> I'm thinking of having one link via radio and another one via a VPN
>lan2lan
>> tunnel.
>> This will be the cheapest wan solution.
>> But I can't figure out how to solve the redundacy part of it.
>>
>> EIGRP is rp that i use. But how will the router detect that one link is
>> down?
>> I will not get any physical link down from the tunnel or the radio
>equipment
>> when the link is down.
>> Any suggestions?
>>
>
>There are some good papers about redundacy on www.networkingunlimited.com

And an entire book "High Availability Network with Cisco" by Vincent Jones.

--
Barry Margolin,
Level(3), 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.

"Barry Margolin" <> wrote in message
news:KB8qb.366$...
>
> And an entire book "High Availability Network with Cisco" by Vincent
Jones.
>

Having a real long troubles getting it trough amazon, europe... damn..

Ivan

I would use GRE/IPSEC on the lan 2 lan and wireless. That way EIGRP
will automaically failover to the other link when a link is down or
not routing.

I would use GRE/IPSEC on the lan 2 lan. That way EIGRP will notice
the downed (or not routed) circuit and automatically failover. I have
done this with frame relay failing to LAN 2 LAN.

"Bengt Ohlen" <> wrote in message
news:gb4qb.2013$...
> I would like to have a redundant link to a building.
> I'm thinking of having one link via radio and another one via a VPN
lan2lan
> tunnel.
> This will be the cheapest wan solution.
> But I can't figure out how to solve the redundacy part of it.
>
> EIGRP is rp that i use. But how will the router detect that one link is
> down?
> I will not get any physical link down from the tunnel or the radio
equipment
> when the link is down.
> Any suggestions?

You need a router in the far building that runs a routing protocol across
each link which uses hello packet exchanges with neighbours (but you need a
router or some intelligent device anyway to terminate the vpn tunnel).

The loss of "hello" packets in the routing traffic from the neighbour router
will give an indication of a broken path, even if the link loss doesnt get
to the router.

Main drawback is that you dont "see" the broken path until hello timeout, so
the convergence time includes hello timeout - ie. 40 seconds with default
OSPF timers for example.

AFAIK EIGRP may not be the best choice for routing protocol here, as it
doesnt seem to exchange hellos continuously with all neighbours under all
conditions - may or may not affect you depending on the routing topology.
>
> TIA
> Bengt
--
Regards

Stephen Hope - remove xx from email to reply

In article <bob6o7$1cd1ue$>,
Ivan Ostres <> wrote:
>"Barry Margolin" <> wrote in message
>news:KB8qb.366$...
>>
>> And an entire book "High Availability Network with Cisco" by Vincent
>Jones.
>>
>
>Having a real long troubles getting it trough amazon, europe... damn..
>
>Ivan

Responding to the original poster's question (Bengt), the specific
problem is not addressed explicitly in my book. There are two basic
ways to approach the problem, using a GRE tunnel to support OSPF (or
RIP, or EIGRP, or other routing protocol) or using a routing protocol
like BGP which works even when routers are not directly connected.

See the white paper "Redundant Routes in IPSec VPNs" on my website
for a discussion of the tradeoffs and examples of both techniques.

Good luck and have fun!
--
Vincent C Jones, Consultant Expert advice and a helping hand
Networking Unlimited, Inc. for those who want to manage and
Tenafly, NJ Phone: 201 568-7810 control their networking destiny
http://www.networkingunlimited.com