Redistributing statics into EIGRP for backup path

[mbroberson1]

(see the attached network diagram)

Senario:

You're network is connected to a vendor's network. You have a primary and secondary link to the vendor network. The secondary link is connected to the vendor network through your secondary site. You are running EIGRP for your main network (primary and secondary locations). You would like to inject static routes to the networks you need to access in the vendor's network. You are thinking about also using a floating static on your primary and secondary routers connected to the vendor.

Any suggestions for the best approach?

Thanks

[Jon Marshall]

Richard

I think that EIGRP is not running between the Vendor and Brandon's network so the Vendor networks are not being advertised to the primary router and the secondary router.

If EIGRP is running between Brandon's network and the Vendor network then i agree with what you say.

Jon

[richard.m.gilbert]

Jon,

Understood. With that part of the config missing from the attachement (routing protocol for the 50.x.x.x net) I guess it is assumed to be constant and advertised. Having said that, since it is assumed that 2 routing processes are running on the 2 routers (10.10.x.x and 10.20.x.x), I would assume that they are redistributing between them. With the connections to the vendor sites (on both routers) being done on fastethernet I would also assume that DUAL would see the alternate path as a feasible successor without any manipulation. The problem, or manipulation needed, comes from forcing the secondary site users to use the route through the primary site instead of the directly attached vendor.

Am I tracking correctly or am I muddying the waters?

Richard

[Jon Marshall]

Richard

Must admit i'm a bit confused. I can't see 2 routing processes on the routers even though there is mention of it in the route-maps. On both routers there is only "router eigrp 1" so i'm unclear as to what it means in the route-map config -

route-map vendor permit 10

description ***Redistribute static into eigrp 20***

match tag 20

My understanding was that EIGRP ran between primary router -> L3 switch -> L3 switch -> secondary router but did not extend to the vendor/business partner routers.

"Am I tracking correctly or am I muddying the waters?"

Not sure, it may well be you are understanding this better than i am ! Guess we'll have to wait on Brandon :-)

Jon

[mbroberson1]

Hi Jon,

I'll try to make things more clear. Sorry for muddying things.

EIGRP is running just like you said:

EIGRP is only running between primary router -> L3 switch -> L3 switch -> secondary router but did not extend to the vendor/business partner routers.

Jon,

What do you mean by:

"I can't see 2 routing processes on the routers even though there is mention of it in the route-maps."

Thanks,

Brandon

[Jon Marshall]

Brandon

You have these comments in your config -

primary router

==============

route-map vendor permit 10

description ***Redistribute static into eigrp 10***

match tag 10

but i can't see an EIGRP 10 process anywhere.

That aside try this config

primary router -

ip route 160.20.50.0 255.255.255.0 50.50.50.2

ip route 160.20.40.0 255.255.255.0 50.50.50.2

ip route 160.20.30.0 255.255.240.0 50.50.50.2

ip route 160.20.20.0 255.255.240.0 50.50.50.2

router eigrp 1

redistribute statics

secondary router

================

ip route 160.20.50.0 255.255.255.0 50.50.50.6 250

ip route 160.20.40.0 255.255.255.0 50.50.50.6 250

ip route 160.20.30.0 255.255.240.0 50.50.50.6 250

ip route 160.20.20.0 255.255.240.0 50.50.50.6 250

router eigrp 1

redistribute static

Jon

[mbroberson1]

Oh,

description ***Redistribute static into eigrp 10***

The 10 is referencing the matched tag number.

Brandon

[richard.m.gilbert]

Brandon,

What protocol are you using to connect to the vendor sites on both sides of your network (primary and secondary)?

Richard

[mbroberson1]

Hi Richard,

I am intending to use static routes on the primary and secondary routers that will be redistributed into EIGRP process 1. There is only one EIGRP process running on the primary and secondary ( and the L3 switches connecting the primary and secondary site)and only referencing the business network (10.0.0.0). Static routes to the vendor network will be redistributed into the EIGRP process 1.

Is this what you mean?

Thanks,

Brandon

[mbroberson1]

Hi Jon,

I put together a more detailed diagram that may help.

Thanks,

Brandon

[Richard Burts]

I am looking at the new diagram and there are several things that do not seem to make sense to me. The primary router is marked as 50.50.50.1/50.50.50.1HSRP and the secondary router is marked as 50.50.50.3/50.50.50.1HSRP. Are they both connected on a layer 2 VLAN running through the vendor network?

Also the VLAN at the primary site is marked as 10.10.0.0/24 but the interface on the primary router is 10.10.1.1 which is in a different subnet. Similarly at the secondary location the VLAN is marked as 10.20.0..0/24 while the router interface is 10.20.1.1 (again a different subnet).

What I am seeing so far it looks to me like the suggestion of a static route on the primary router and a floating static on the secondary router should work.

HTH

Rick

[mbroberson1]

Rick,

Sorry,

that should listed as 10.10.1.0/24 for the vlan at then primary, and 10.20.1.0/24 at the secondary site. Yes there is a L2 vlan for the HSRP running through the vendor switch.

Thanks,

Brandon

[Richard Burts]

Brandon

Thanks for the clarification. having taken a closer look at the config I have a couple of other comments.

The interface configuration of both routers shows the subnet/VLAN as a /29:

ip address 50.50.50.1 255.255.255.248

but if this is the case then 50.50.50.8 is the subnet address of the next subnet and not a host address. Therefore it is not an appropriate next hop in the static routes.

Also both routers have a floating default route with the next hop of 50.50.50.8 and the same administrative distance. I would have thought that the AD of the primary router would be better/lower than the AD of the secondary router.

Another thought is that if you made the static routes to the vendor on the secondary router to be floating static routes then it means that these routes get into the routing table only when the primary routes have failed. The way it is configured now the secondary router will have those static routes in its routing table and if any packet happened to come to it, the packet would be forwarded to the vendor by the secondary router rather than forwarding it to the primary - which is what I understand the desired behavior to be.

HTH

Rick

[mbroberson1]

Rick,

Thanks for your reply. I'll post a new diagram soon with correct addressing. Initially when I posted I was thinking that maybe only posting part of the diagram and sanitizing the addressing would be enough. I was very wrong. What I'll do is post a new diagram soon that more reflects the addressing being used. I threw the previous diagram together and with the wrong subnetmask info.

Thanks,

Brandon

[mbroberson1]

Rick & Jon,

I am posting here now a 4th network diagram. I really appreciated all the feedback and suggestions you have given.

We will call the business site your corporate network side. On your corporate network side you have many subnets under the major 10.0.0.0 network.

At the coporate primary site we will call 10.10.1.x/24 vlan 1, and at the corporate secondary site we will call 10.20.1.x/24 vlan 1. At both the primary and secondary corporate sites there are for example:

primary site:

vlan 2 - 10.10.2.x/24

vlan 3 - 10.10.3.x/24

vlan 4 - 10.10.4.x/24

etc... with many more vlans following this same scheme.

secondary site:

vlan 2 - 10.20.2.x/24

vlan 3 - 10.20.3.x/24

vlan 4 - 10.20.4.x/24

etc... with many more vlans following this same scheme.

You are running 1 EIGRP accross your corporate enterprise for the major network 10.0.0.0.

You are considering re-disrtibuting static routes to the vendor networks into your EIGRP process.

Vendor networks will be:

160.20.50.0/24

160.20.60.0/24

160.50.70.0/24

etc...

HTH & Thanks!

Brandon

[Jon Marshall]

Brandon

From the diagram i still think the best approach is floating statics unless Rick spots anything i am missing ?

So to update config -

primary router -

ip route 160.20.50.0 255.255.255.0

10.99.0.68

ip route 160.20.40.0 255.255.255.0 10.99.0.68

ip route 160.20.30.0 255.255.240.0 10.99.0.68

ip route 160.20.20.0 255.255.240.0 10.99.0.68

router eigrp 1

redistribute statics

secondary router

================

ip route 160.20.50.0 255.255.255.0 10.99.0.68 250

ip route 160.20.40.0 255.255.255.0 10.99.0.68 250

ip route 160.20.30.0 255.255.240.0 10.99.0.68 250

ip route 160.20.20.0 255.255.240.0 10.99.0.68 250

router eigrp 1

redistribute static

The secondary router statics will only be used if the primary router fails.

Jon