RIP Default Route Not Being Distributed to Spoke Sites
Presenting Symptom
Spoke sites in a hub-and-spoke RIP network cannot reach the internet because the default route configured on the hub router is not being advertised to the spokes.
Network Context
The network consists of a hub router (HQ) and two spoke routers (Branch1, Branch2) connected via serial links. All routers run RIP version 2. The hub router has a static default route pointing to an upstream ISP router. The spokes should learn this default route via RIP to reach external networks. IOS version is 15.x.
Diagnostic Steps
Check RIP routing table on a spoke router
show ip route ripR* 0.0.0.0/0 [120/1] via 10.0.0.1, 00:00:15, Serial0/0/0
If no default route appears, the spoke is not receiving it. If a default route appears, the issue may be elsewhere.
Verify RIP configuration on the hub router
show running-config | section router riprouter rip version 2 network 10.0.0.0 default-information originate
The 'default-information originate' command is required to advertise the default route. If missing, the hub will not propagate the default route.
Check if the static default route exists on the hub
show ip route staticS* 0.0.0.0/0 [1/0] via 203.0.113.1
The static default route must be present. If not, the hub has no default route to advertise.
Debug RIP updates on the hub
debug ip ripRIP: sending v2 update to 224.0.0.9 via Serial0/0/0 (10.0.0.1)
RIP: build update entries
0.0.0.0/0 via 0.0.0.0, metric 1, tag 0If the default route is not included in the update, the 'default-information originate' command may be missing or misconfigured. If it is included, the issue may be on the spoke side (e.g., passive interface).
Root Cause
The hub router is missing the 'default-information originate' command under the RIP process. Without this command, RIP does not advertise the static default route to RIP neighbors.
Resolution
Verification
On a spoke router, run: show ip route rip Expected output includes: R* 0.0.0.0/0 [120/1] via 10.0.0.1, 00:00:15, Serial0/0/0 Also verify connectivity with a ping to an external IP (e.g., ping 8.8.8.8).
Prevention
["Always include 'default-information originate' on the hub router when using RIP to distribute a default route.","Use route filtering (distribute-list) only when necessary to avoid accidentally blocking default routes.","Document and standardize hub-and-spoke RIP configurations to ensure consistent default route propagation."]
CCNA Exam Relevance
On the CCNA 200-301 exam, this scenario tests knowledge of RIP default route propagation. Expect multiple-choice questions asking which command enables default route advertisement in RIP, or troubleshooting questions where you must identify missing 'default-information originate'. The key fact is that RIP does not advertise default routes by default; the 'default-information originate' command is required.
Exam Tips
Remember that 'default-information originate' is needed for RIP to advertise a default route; it is not automatic like in OSPF.
The exam may present a scenario where a static default route exists but is not being learned by RIP neighbors — the fix is to add 'default-information originate' under router rip.
Know the difference: 'default-information originate' in RIP vs 'default-information originate always' in OSPF.
Commands Used in This Scenario
debug ip rip
Enables real-time debugging of RIP routing updates to troubleshoot routing issues by displaying sent and received RIP updates.
show ip route
Displays the current IP routing table on a Cisco router, used to verify routes, check next-hop addresses, and troubleshoot connectivity issues.
show running-config
Displays the current active configuration in DRAM, showing all non-default settings.
Test Your CCNA Knowledge
Practice with scenario-based questions to prepare for the CCNA 200-301 exam.
Practice CCNA Questions