[IT168 Technology] In the course of router setup, there is no abnormal network communication. The router can successfully route the packet to the destination network, but the packet sent from the router fails to transmit. The setting of the fault is that the router fails to ping the target network. This type of fault is more common. Let's look at a typical case below.
After the network configuration was completed, the administrator discovered that when the network connectivity was tested, it was sent from the PC (220.127.116.11) to the target network (18.104.22.168/26). During ping, router R1 can successfully forward packets. However, when ping is sent from R1 to the destination network (22.214.171.124/26), a ping failure occurs.
The paths pinged. Check the routing table of R1. The destination address 126.96.36.199 can match the 0.0.0.0/0 in the routing table. Check the routing tables of R2, R3, and R4. You can find routing entries that match the destination address.
The path that the ICMP echo response packet traverses. In order to complete this step, it is necessary to explicitly respond to the source address of the packet. When the PC sends a ping, the destination address of the response packet is 188.8.131.52. When router R1 sends a ping, the destination address of the reply response packet is 184.108.40.206. According to the routing table of R4, a routing entry matching 220.127.116.11 is found, and no routing entry matching the target address 18.104.22.168 is found. It appears that the ICMP echo response packet was discarded during R4 processing, so a pmg failure occurred when sending a ping from R1 to the target network R4 (22.214.171.124/26).
A router setting was used to add a static route to 126.96.36.199/30 on router R4 with the next hop address of 188.8.131.52. After completion, when R1 sends a ping to R4, it is found that the router failed to resolve the packet.
Failed ping fault network failure Although it will not affect the normal network communication, the process of elimination is also very simple, usually through simple router settings can be resolved. However, in the analysis and elimination of network failures, we must consider the complete communication process.