Verification Checklist & CLI Reference

Real-world CLI verification commands for EIGRP summarization, stub routing, route filtering, and redistribution. Each table shows expected healthy output vs failure indicators, helping you validate your configuration during lab work or production change windows.

Author: Hrishi Pradhan

Level: Basic to Advanced

Tables: 4 Verification

Blueprint: Production CLI

Verification Checklist

Compare your CLI output with expected healthy states and failure indicators

Premium Content

How to Use This Checklist

Run each command on your router. Compare your output with the "Expected Output (Healthy)" column. If you see anything matching the "Failure Indicator" column, refer to the Troubleshooting Vault (Part 3) for the fix.

Command Expected Output (Healthy) Failure Indicator

Command	Expected Output (Healthy)	Failure Indicator
`show ip route \| include Null0`	D 10.1.0.0/16 is a summary, 00:15:23, Null0 Summary route installed with Null0 discard (AD 5). Null0 protection active.	(empty output — no Null0 route) No Null0 route. Summary removed or never configured. Blackhole risk for unassigned subnets.
`show ip protocols \| section Stub`	EIGRP stub, receive-only Connected Summary Stub routing configured with connected + summary options.	(empty output — no stub configuration) Stub routing not configured. This router will participate in query propagation.

show ip route | include Null0

D 10.1.0.0/16 is a summary, 00:15:23, Null0

Summary route installed with Null0 discard (AD 5). Null0 protection active.

(empty output — no Null0 route)

No Null0 route. Summary removed or never configured. Blackhole risk for unassigned subnets.

show ip protocols | section Stub

EIGRP stub, receive-only
  Connected
  Summary

Stub routing configured with connected + summary options.

(empty output — no stub configuration)

Stub routing not configured. This router will participate in query propagation.

show ip eigrp topology
(filtered routes)

P 10.1.10.0/24, 1 successors, FD is 158720
  via 10.1.12.2 (158720/156160), GigabitEthernet0/1

P 10.1.20.0/24, 1 successors, FD is 158720
  via 10.1.13.2 (158720/156160), GigabitEthernet0/2

! Note: Filtered subnet 10.1.30.0/24 is absent
! Filtering is working as intended

Filtered routes do not appear in topology table. Distribute-list applied correctly.

P 10.1.10.0/24, 1 successors, FD is 158720
  via 10.1.12.2 (158720/156160), GigabitEthernet0/1

P 10.1.20.0/24, 1 successors, FD is 158720
  via 10.1.13.2 (158720/156160), GigabitEthernet0/2

P 10.1.30.0/24, 1 successors, FD is 158720  ← Filter NOT working
  via 10.1.12.2 (158720/156160), GigabitEthernet0/1

Filtered subnet 10.1.30.0/24 still appears. Distribute-list misconfigured or ACL does not match.

show ip route eigrp
(external routes)

D EX  172.16.0.0/16 [170/30720] via 10.0.0.2, 00:15:23, Gi0/0
D EX  172.17.0.0/16 [170/30720] via 10.0.0.2, 00:15:23, Gi0/0

! AD 170 = external routes (redistributed)
! Tag = 100 (visible with 'show ip route 172.16.0.0 detail')

Redistributed routes show external AD 170. Route tags applied correctly.

D     172.16.0.0/16 [90/30720] via 10.0.0.2, 00:15:23, Gi0/0

! AD 90 = internal — route was NOT tagged properly
! Re-redistribution risk — loop possible

Redistributed routes showing internal AD — redistribution misconfigured or route tag not applied.

Production CLI Blueprint

Summarization + stub + filtering + redistribution reference

Reference

How to Use This Blueprint

Copy these commands into your production or lab routers. Replace 1234 with your AS number and update interface names to match your topology. Each section is independent — use only what you need.

Route Summarization with Null0 Protection

interface GigabitEthernet0/1
 ip summary-address eigrp 1234 10.16.0.0 255.255.240.0
 ! Summary 10.16.0.0/20 advertised
 ! Auto-installs Null0 route with AD 5

! Verify
! show ip route | include Null0
! show ip route | include summary

Stub Routing Configuration

router eigrp 1234
 eigrp stub connected summary
 ! Advertise connected + summary routes only
 ! Never forward queries to other stub routers

! Verify
! show ip protocols | section Stub
! show ip eigrp neighbors detail

Route Filtering with Prefix-List

! Define prefix-list
ip prefix-list FILTER permit 10.1.10.0/24
ip prefix-list FILTER permit 10.1.20.0/24

! Apply to EIGRP process
router eigrp 1234
 distribute-list prefix FILTER in GigabitEthernet0/1

! Verify filtering
! show ip eigrp topology | include 10.1.30
! Should be absent if filtered correctly

Redistribution with Route-Map and Tagging

! Prefix-list of routes to redistribute
ip prefix-list REDIST permit 172.16.0.0/16 le 24
ip prefix-list REDIST deny 0.0.0.0/0 le 32

! Route-map with tag and metric
route-map OSPF_TO_EIGRP permit 10
 match ip address prefix-list REDIST
 set tag 100
 set metric 100000 100 255 1 1500

! Apply
router eigrp 1234
 redistribute ospf 1 route-map OSPF_TO_EIGRP
 passive-interface default
 no passive-interface GigabitEthernet0/0

! Verify
! show ip route eigrp | include EX
! show ip route 172.16.0.0 detail  (look for Tag 100)

Combined Production Setup

! Boundary router with full production configuration
router eigrp 1234
 eigrp stub connected summary
 redistribute ospf 1 route-map OSPF_TO_EIGRP
 passive-interface default
 no passive-interface GigabitEthernet0/0
 distribute-list prefix FILTER in GigabitEthernet0/0

interface GigabitEthernet0/1
 ip summary-address eigrp 1234 10.16.0.0 255.255.240.0

! Verify end state
show ip route | include Null0
show ip protocols | section Stub
show ip route eigrp | include EX

Production Warning

Before deploying summarization in production, verify that the summary mask correctly encompasses all intended subnets. An incorrect mask can blackhole legitimate traffic. Always check show ip route | include Null0 after applying summarization, and confirm the summary does not overlap with other routing domains.