Eigrp Summarization

[mjensen323]

I recently deployed EIGRP via 10 Gig fiber.  Everything is working, but I feel like some summarization may make the network faster, etc. 

The network design is currently- 

Internet < - ASA <- Core 3750-x stack <-> 4500-X

Core Stack contains Cisco Call Manager, 2 x WLC, etc. 2 - 10 Gig connections to the UCS / Nimble Array

4500-X stack is in VSS, 2 - 10 Gig Connections to 3750-X

Each remote is connected via 10 Gig fiber to the 4500-X

4500-X is the main distribution with EIGRP with the 10.x being the adjacency.

router eigrp 100
network 10.0.2.0 0.0.0.7
network 10.0.3.0 0.0.0.7
network 10.0.5.0 0.0.0.7
network 10.0.7.0 0.0.0.7
network 10.0.9.0 0.0.0.7
network 10.0.10.0 0.0.0.7
network 10.0.100.0 0.0.0.7
network 10.0.200.0 0.0.0.7
network 192.168.0.0 0.0.255.255 (This is all the data / voice / etc..)
redistribute static metric 10000 10 255 1 1500   (this goes to the ASA)
eigrp router-id 1.1.1.1

This is sh ip route on the Distribution

S* 0.0.0.0/0 [1/0] via 192.168.210.2
1.0.0.0/32 is subnetted, 1 subnets
C 1.1.1.1 is directly connected, Loopback0
10.0.0.0/8 is variably subnetted, 16 subnets, 2 masks
C 10.0.2.0/29 is directly connected, Port-channel2
L 10.0.2.1/32 is directly connected, Port-channel2
C 10.0.3.0/29 is directly connected, Port-channel3
L 10.0.3.1/32 is directly connected, Port-channel3
D 10.0.4.0/29 [90/768] via 10.0.2.2, 16:30:03, Port-channel2
C 10.0.5.0/29 is directly connected, Port-channel5
L 10.0.5.1/32 is directly connected, Port-channel5
C 10.0.7.0/29 is directly connected, Port-channel7
L 10.0.7.1/32 is directly connected, Port-channel7
D 10.0.8.0/29 [90/768] via 10.0.3.2, 17:03:14, Port-channel3
C 10.0.9.0/29 is directly connected, Port-channel9
L 10.0.9.1/32 is directly connected, Port-channel9
C 10.0.10.0/29 is directly connected, Port-channel100
L 10.0.10.1/32 is directly connected, Port-channel100
C 10.0.200.0/29 is directly connected, Port-channel200
L 10.0.200.1/32 is directly connected, Port-channel200
D 192.168.3.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.8.0/22 [90/3072] via 10.0.10.2, 17:03:14, Port-channel100
D 192.168.13.0/24 [90/3072] via 10.0.10.2, 17:03:14, Port-channel100
D 192.168.14.0/24 [90/3072] via 10.0.10.2, 17:03:14, Port-channel100
D 192.168.20.0/24 [90/3072] via 10.0.2.2, 16:30:03, Port-channel2
D 192.168.21.0/24 [90/3072] via 10.0.2.2, 16:30:03, Port-channel2
D 192.168.22.0/24 [90/3072] via 10.0.2.2, 16:30:03, Port-channel2
D 192.168.30.0/24 [90/3072] via 10.0.3.2, 17:03:14, Port-channel3
D 192.168.31.0/24 [90/3072] via 10.0.3.2, 17:03:14, Port-channel3
D 192.168.32.0/24 [90/3072] via 10.0.3.2, 17:03:14, Port-channel3
D 192.168.40.0/24 [90/3328] via 10.0.2.2, 16:27:33, Port-channel2
D 192.168.41.0/24 [90/3328] via 10.0.2.2, 16:27:33, Port-channel2
D 192.168.42.0/24 [90/3328] via 10.0.2.2, 16:27:33, Port-channel2
D 192.168.50.0/24 [90/3072] via 10.0.5.2, 16:59:30, Port-channel5
D 192.168.51.0/24 [90/3072] via 10.0.5.2, 16:59:30, Port-channel5
D 192.168.52.0/24 [90/3072] via 10.0.5.2, 16:59:30, Port-channel5
D 192.168.60.0/24 [90/3328] via 10.0.2.2, 16:27:33, Port-channel2
D 192.168.61.0/24 [90/3328] via 10.0.2.2, 16:27:33, Port-channel2
D 192.168.62.0/24 [90/3328] via 10.0.2.2, 16:27:33, Port-channel2
D 192.168.70.0/24 [90/3072] via 10.0.7.2, 17:03:13, Port-channel7
D 192.168.71.0/24 [90/3072] via 10.0.7.2, 17:03:13, Port-channel7
D 192.168.72.0/24 [90/3072] via 10.0.7.2, 17:03:13, Port-channel7
D 192.168.80.0/22 [90/3328] via 10.0.3.2, 16:22:43, Port-channel3
D 192.168.84.0/24 [90/3328] via 10.0.3.2, 16:22:43, Port-channel3
D 192.168.85.0/24 [90/3328] via 10.0.3.2, 16:22:43, Port-channel3
D 192.168.86.0/24 [90/3328] via 10.0.3.2, 16:22:16, Port-channel3
D 192.168.90.0/24 [90/3072] via 10.0.9.2, 17:03:13, Port-channel9
D 192.168.91.0/24 [90/3072] via 10.0.9.2, 17:03:13, Port-channel9
D 192.168.92.0/24 [90/3072] via 10.0.9.2, 17:03:13, Port-channel9
D 192.168.98.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.99.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.100.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.101.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.115.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.116.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.126.0/24 [90/3072] via 10.0.10.2, 17:03:14, Port-channel100
D 192.168.127.0/24 [90/3072] via 10.0.10.2, 17:03:14, Port-channel100
D 192.168.128.0/24 [90/3072] via 10.0.10.2, 17:03:14, Port-channel100
D 192.168.136.0/21 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.144.0/20 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.160.0/21 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.169.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.200.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.201.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.210.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.220.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.221.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.222.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.223.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.224.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200
D 192.168.225.0/24 [90/3072] via 10.0.200.2, 17:03:11, Port-channel200

And this is a sample building that only utilizes 192.168.50.x, 51.x, 52.x

All buildings are point to point links with only a single path

router eigrp 100
network 10.0.5.0 0.0.0.7 -> To the 4500-X (20 gig)
network 192.168.50.0 Data
network 192.168.51.0 Voice
network 192.168.52.0 Access Points
eigrp router-id 1.1.1.5

show ip route:

D*EX 0.0.0.0/0 [170/258816] via 10.0.5.1, 17:00:59, Port-channel5
1.0.0.0/32 is subnetted, 1 subnets
C 1.1.1.5 is directly connected, Loopback0
10.0.0.0/8 is variably subnetted, 10 subnets, 2 masks
D 10.0.2.0/29 [90/768] via 10.0.5.1, 17:00:59, Port-channel5
D 10.0.3.0/29 [90/768] via 10.0.5.1, 17:00:59, Port-channel5
D 10.0.4.0/29 [90/1024] via 10.0.5.1, 16:31:32, Port-channel5
C 10.0.5.0/29 is directly connected, Port-channel5
L 10.0.5.2/32 is directly connected, Port-channel5
D 10.0.7.0/29 [90/512] via 10.0.5.1, 17:00:59, Port-channel5
D 10.0.8.0/29 [90/1024] via 10.0.5.1, 17:00:59, Port-channel5
D 10.0.9.0/29 [90/512] via 10.0.5.1, 17:00:59, Port-channel5
D 10.0.10.0/29 [90/512] via 10.0.5.1, 17:00:59, Port-channel5
D 10.0.200.0/29 [90/512] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.3.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.8.0/22 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.13.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.14.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.20.0/24 [90/3328] via 10.0.5.1, 16:31:32, Port-channel5
D 192.168.21.0/24 [90/3328] via 10.0.5.1, 16:31:32, Port-channel5
D 192.168.22.0/24 [90/3328] via 10.0.5.1, 16:31:32, Port-channel5
D 192.168.30.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.31.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.32.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.40.0/24 [90/3584] via 10.0.5.1, 16:29:02, Port-channel5
D 192.168.41.0/24 [90/3584] via 10.0.5.1, 16:29:02, Port-channel5
D 192.168.42.0/24 [90/3584] via 10.0.5.1, 16:29:02, Port-channel5
192.168.50.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.50.0/24 is directly connected, Vlan50
L 192.168.50.1/32 is directly connected, Vlan50
192.168.51.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.51.0/24 is directly connected, Vlan51
L 192.168.51.1/32 is directly connected, Vlan51
192.168.52.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.52.0/24 is directly connected, Vlan52
L 192.168.52.1/32 is directly connected, Vlan52
D 192.168.60.0/24 [90/3584] via 10.0.5.1, 16:29:02, Port-channel5
D 192.168.61.0/24 [90/3584] via 10.0.5.1, 16:29:02, Port-channel5
D 192.168.62.0/24 [90/3584] via 10.0.5.1, 16:29:02, Port-channel5
D 192.168.70.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.71.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.72.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.80.0/22 [90/3584] via 10.0.5.1, 16:24:12, Port-channel5
D 192.168.84.0/24 [90/3584] via 10.0.5.1, 16:24:12, Port-channel5
D 192.168.85.0/24 [90/3584] via 10.0.5.1, 16:24:12, Port-channel5
D 192.168.86.0/24 [90/3584] via 10.0.5.1, 16:23:45, Port-channel5
D 192.168.90.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.91.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.92.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.98.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.99.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.100.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.101.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.115.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.116.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.126.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.127.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.128.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.136.0/21 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.144.0/20 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.160.0/21 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.169.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.200.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.201.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.210.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.220.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.221.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.222.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.223.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5
D 192.168.224.0/24 [90/3328] via 10.0.5.1, 17:00:59, Port-channel5

[Meheretab Mengistu]

Hi,

You can lower the number of routes in the routing table of remote sites by sending default routes only. Here is a sample config:

router eigrp 100
network 10.0.2.0 0.0.0.7
network 10.0.3.0 0.0.0.7
network 10.0.5.0 0.0.0.7
network 10.0.7.0 0.0.0.7
network 10.0.9.0 0.0.0.7
network 10.0.10.0 0.0.0.7
network 10.0.100.0 0.0.0.7
network 10.0.200.0 0.0.0.7
network 192.168.0.0 0.0.255.255
redistribute static metric 10000 10 255 1 1500
eigrp router-id 1.1.1.1

distribute-list 10 out interface Port-channel 5 **

!

access-list 10 permit host 0.0.0.0

!

**You will need to add  "distribute-list" for each neighbor though.

I would also make the remote eigrp connection "stub" since there is a single upstream connections. The configuration would be as follows:

router eigrp 100
network 10.0.5.0 0.0.0.7 
network 192.168.50.0 Data
network 192.168.51.0 Voice
network 192.168.52.0 Access Points

eigrp stub

!

HTH,

Meheretab

[mjensen323]

Thanks for the reply. I really appreciate it. 

If I had a site design as below, but then another building was linked to it, would that also be a stub?

[mjensen323]

And by making the route changes / distribution lists, does that speed up the routing or make a network impact?

[Meheretab Mengistu · Accepted solution]

---

@mjensen323 wrote:

And by making the route changes / distribution lists, does that speed up the routing or make a network impact?

---

If a link is down in one of the remote routers and there is no feasible successor in the topology table, all routers will participate in calculating the route. However, if you provide for edge routers/switches with single uplink a default route only, they will not participate in DUAL algorithm best route calculation; that will lower the overhead on the CPU. 

If you configure the edge routers as an 'eigrp stub', they will not participate in EIGRP Query which will contribute for faster convergence. 

---

@mjensen323 wrote:

If I had a site design as below, but then another building was linked to it, would that also be a stub?

If you add another building and connect it to the distribution router, I would configure it as a stub router.

Here are important things we need to remember about eigrp stub routers:-

- Neighbors do not send queries to a stub router.

- Any network that is learned via a stub router is not advertised to any further neighbor.

- Only specific networks are advertised by a stub router to its neighbor. The default subset of networks are "connected" and "summary"; however, you have other options like static, redistributed, leak-map, ..

HTH,

Meheretab