if a route fails in a multipath route?

eantoranz · 07-02-2005, 02:10 AM

What happens if only one of many routes in a multpiath rote fails?

Suppose that there are three gateways thru 3 different ISPs connected to a single host.

eth0 GW: 201.201.201.201
eth1 GW: 202.202.202.202
eth2 GW: 203.203.203.203.

I would do this:

Code:

ip route add default netxhop via 201.201.201.201 dev eth0 nexthop via 202.202.202.202 dev eth1 nexthop via 203.203.203.203 dev eth2

Perfect... now I have a single default route joining all three connections. But what happens in case one of the three connections fails? Will iproute2 "deactivate" it from the multipath route automaginally until it comes back online again?

Matir · 07-03-2005, 01:22 PM

iproute2 should, as I understand it, drop the down route until it comes back up. The first time it tries to send packets over the down route, you'll probably see some latency, but then it should come back up, I believe.

eantoranz · 07-03-2005, 01:31 PM

the whole multipath route?

Matir · 07-03-2005, 01:40 PM

It should just bring down the single component, I believe. That's how it handles bonding anyway.

eantoranz · 07-03-2005, 01:51 PM

Good to know. What's bonding?

(I'm seriously thinking about dropping my Guru status after this question

)

Matir · 07-03-2005, 02:03 PM

http://linux-ip.net/html/ether-bonding.html