The users feedback to fail in communicating with the PC underlying R2630 on R2611. Networking：R2611(E0)----(E1)R2630（E0）----PC
Ensure the users not to configure PC gateway, it is normal after configuring. Analysis process： 1. the E0 address is communicated from PC to router R2630, which means the link is normal. 2. the E0 address is communicated from R2630 to router R2611, which means the link is normal. 3. execute “ping －a X.X.X.X (E0 address of R2630）X.X.X.X(E0 address of R2611) on R2630，it is communicated too, so the route between them is normal. 4. both link and route are normal, the problem may lie in PC. Check the IP configuration of net card, and detect the address is not the E0 address of router R2630, configure the E0 address of R2630 as the gateway of PC, PC can communicate with the E0 address of router 2611, so does 2611.
The main reasons are: 1. link malfunction 2. network route is uncommunicated 3. not configure PC gateway or it is error.