Avaya G250 Administration page 298

Configuring monitoring applications
Figure 33: Sample Ethereal screen
Identifying the interface
The G250/G350's packet sniffing service can capture also non-Ethernet packets, such as
frame-relay and PPP, into the capture file. This is achieved by wrapping non-Ethernet packets in
a dummy Ethernet header to allow the packets to be stored in a libpcap format. This allows you
to analyze packets on all the device interfaces.
The dummy Ethernet headers are allocated according to the original packet type. Dummy
Ethernet headers start with 00:00. Therefore if the source or destination address of a packet
you are viewing in Ethereal starts with 00:00, this indicates the packet is a non-Ethernet packet.
For example, see the highlighted destination address of the packet appearing in the middle
pane in Figure
The dummy Ethernet header is identified by special MAC addresses. Packets sent from a
non-Ethernet interface are identified with an SA address in the format 00:01:00:00:xx and a DA
address which holds the interface index. Packets received over a non-Ethernet interface are
identified with DA address in the format 00:01:00:00:xx and an SA address which holds the
interface index. The show capture-dummy-headers command displays the dummy header
addresses and their meaning according to the current configuration.
298 Administration for the Avaya G250 and Avaya G350 Media Gateways
33.