A routing loop occurs after routes are summarized on an AR2240

Root cause: On the live network, whether packets sent from Router2 to 192.168.128.161 through Router1 or ME60B depends on the 24GE card connected between Router1 and Router2. The 24GE card is the high-end LAN card that provides the route forwarding function (enabled by default), but cannot download a complete IP routing table. Router1 learns routes to 192.168.128.160/29 through OSPF. When packets reach Router1, Router1 sends the packets to Router2, causing a loop. To eliminate the loop, disable the route forwarding function of the high-end LAN card. Subsequently, packets received by the high-end LAN card are sent to the sub-core CPU for forwarding.
Run the set workmode lan-card l3centralize command in the system view to disable the route forwarding function of high-end LAN card. In this case, Router2 can ping 192.168.128.161 successfully.
Procedure:
1. Check route table and forwarding entries.
2. Perform tracert starting from R3.
3. Run the display traffic policy statistics interface interface-type interface-number { inbound | outbound } command on R1 and R2 respectively to collect traffic statistics on the interfaces that connect R1 and R2.
For details, see A Routing Loop Occurs After Routes Are Summarized on an AR2240.

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