Nortel Networks NN46110-602 manual Capture types, Physical interface captures, Tunnel captures

106 Chapter 5 Packet capture

Capture types

The VPN Router captures packets from the following sources:

•Physical interfaces, including the following:

—Asynchronous digital subscriber line (ADSL)/asynchronous transfer mode (ATM)

—Fast Ethernet and Gigabit Ethernet, including traffic that is not directed to the VPN Router (promiscuous mode)

—Dial (V.90 and asynchronous Point-to-Point Protocol [PPP])

—Integrated services digital network basic-rate interface (ISDN BRI)

—Serial

•Tunnels

—Branch offices (all types)

—User tunnels

•All IP traffic on the VPN Router

The following sections describe each type of capture.

Physical interface captures

Packet capture of traffic on a physical interface can help you troubleshoot

Layer 2 issues, connectivity issues, and performance issues. The Layer 2 header is saved in the PCAP file for each packet. You can convert PCAP files containing traffic captured on a physical interface to most file formats, including Network General Sniffer.

Tunnel captures

You can use packet capture of traffic over tunnels to help troubleshoot a specific tunnel problem. For example, you can create a tunnel capture object to diagnose the following types of problems:

•a protocol not working for a particular user

•performance issues for a particular user

•Open Shortest Path First (OSPF) not working properly inside a specific branch office tunnel

NN46110-602