Hi,
i attached my network schema.
This is routed network.When L1 is down i must edit default gw onRB1,RB4,RB5,RB6.
When L2 is down i must edit default gw on RB2,RB6,RB5,RB4
How can i make easiest back up configuration for situations when L1 or L2 is down.
Can i make Interface/Gre between RB1 - RB2 and then edit GW onli on RB1 or RB2?Is this good idea?
Thank you very much.
lubo
Seems to me the simplest solution would be an additional default route on RB1 that points to RB2, and an additional default route on RB2 that points to RB1. Set this route with a slightly higher distance. When link1 fails, R1 will reroute all internet traffic to R2. When link2 fails, R2 will reroute all internet traffic to R1.
My idea was ,when L1 is down,default GW is RB2,when L2 is down,default GW is RB1
I created GRE tunnel like in attached file.
But routing does not work.
rmmccann: How you can set default route on RB1 that direct points to RB2 trought RB4,RB5,RB6?
lubo
In this case, because RB4, RB5, and RB6 traffic always flows through RB1 or RB2, you can simply disregard their default route and take care of it futher upstream.
The packets will still go to R1, however R1 will know if L1 is down and if so, it will re-route that traffic to R2 via the secondary default route. Same goes for R2 with L2.
Can R1 and R2 communicate with each other directly without the use of a tunnel? If so, you don’t need the tunnel.
Let’s say R1 is 192.168.1.1 and R2 is 192.168.2.1
On R1, create a route like:
/ip route add distance=2 gateway=192.168.2.1
On R2, create a route like:
/ip route add distance=2 gateway=192.168.1.1
Now, if you’re looking for complete failover in the event that R1 or R2 is completely offline, you’ll either need to implement some type of routing protocol or utilize something like VRRP.
my configuration is like this:
RB4 eth1 IP:1.1.1.1/24 eth2 IP:1.1.2.1/24 GW IP:1.1.2.2/24
RB5 eth1 IP:1.1.2.2/24 eth2 IP:1.1.3.1/24 GW IP:1.1.3.2/24
RB6 eth1 IP:1.1.3.2/24 eth2 IP:1.1.4.1/24 GW IP:1.1.4.2/24
RB2 eth1 IP:1.1.4.2/24 eth2 IP:1.1.5.1/24 GW IP:1.1.5.2/24
RB3 eth1 IP:1.1.6.2/24 eth2 IP:1.1.7.1/24 GW IP:1.1.7.2/24
RB1 eth1 IP:1.1.7.1/24 eth2 IP:1.1.5.3/24 GW IP:1.1.5.2/24
RBGW is last router of my network
rmmccann,possible default GW for R1 is RBGW or RB4 only, not RB2 normaly
If all is right
PC1 use L1
RB2 use L2 (but trought RB4,RB5,RB6 and RB2)
lubo
OK, I think I follow what’s going on here now. I missed the RBGW in the diagram, however my suggestion should still apply.
What I would do is make sure all routers that have a direct connection to RB1 use RB1 as their default gateway. For routers with a direct connection to RB2, use RB2 as their default gateway. In the case of RB5, you can set it to use either RB4 or RB6 depending on which way you’d want traffic to “normally” flow.
RB1 can use RBGW as it’s default gateway via L1. RB2 can use RBGW as it’s default gateway via L2.
Set up either a GRE or IPIP tunnel between RB1 and RB2. Assign IPs to both ends of the tunnel.
On RB1, set up an additional default route with a slightly higher distance and use RB2’s tunnel IP as the gateway address.
On RB2, set up an additional default route with a slightly higher distance and use RB1’s tunnel IP as the gateway address.
Now, if L1 fails, RB1 will automatically route traffic over the tunnel to RB2 and out to the internet. If L2 fails, RB2 will route traffic over the tunnel to RB1 and out to the internet.
By doing it this way, it should automatically re-route for you and you won’t have to manually change anything.