Eigrp update packet capture

Popular Posts. BGP States July 09, Random Posts. Menu Footer Widget. Home About Contact Us. This is from the Cisco documentation :. When a new neighbor is discovered , update packets are sent so the neighbor can build up its topology table.

In this case, update packets are unicast. In other cases, such as a link cost change, updates are multicast. Your email address will not be published. Comments Thanks for these! Thanks, Mario. R1's physical interface IP address is R1 clear ip eigrp neighbors. Below is wireshark capture of R1 sending unicast update to R2. This Query Packet is sent as a multicast on a multicast address If no response is received in 16 attempts, the EIGRP neighbor relationship is reset with that neighbor.

Query Packets have OPCode of 3. Reply Packets have OPCode of 4. Both Ack and Hello Packets have Opcode 5. With graceful shutdown, a goodbye message is broadcast when an EIGRP routing process is shut down, to inform adjacent peers about the impending topology change. Reliable means that when we send a packet we want to get an acknowledgment from the other side to make sure that they received it.

Hello packets are sent between routers in order to form adjacencies. As you can see R1 is sending 3 hello packets meant for R2, R3 and R4. There are 2 questions that we can ask ourselves here:. Sending 3 packets on the same link is not very useful so instead of doing this EIGRP will send hello packets by using multicast on a multi-access network like Ethernet. So which packets should be acknowledged?