As an IT administrator, it is important to be able to monitor traffic on subinterfaces, especially if multiple networks are connected to the same device. This is especially true in the case of a Cisco 1941W router, which supports multiple VLANs and subinterfaces. Monitoring traffic on subinterfaces can be done in several ways, depending on what kind of information is needed.
The first step to monitoring traffic on subinterfaces is to configure the VLANs and subinterfaces. This can be done by using the command line interface (CLI) or the web interface. To configure VLANs, use the \vlan\ command, followed by the VLAN ID and name. To configure a subinterface, use the \interface\ command, followed by the interface name and the VLAN ID.
Once the VLANs and subinterfaces have been configured, the next step is to enable traffic monitoring. This is done by using the \monitor session\ command, followed by the session number and the source and destination interface. This will enable monitoring on the specified interfaces.
Once monitoring is enabled, the next step is to use the \show monitor session\ command to view the traffic. This command will display a list of all the monitored sessions. It will also show the type of traffic, such as UDP, TCP, ICMP, and so on. The command will also show the source and destination IP addresses, as well as the protocol and port numbers.
Once the traffic is being monitored, the next step is to use the \show traffic rate\ command to view the rate of traffic on the subinterfaces. This command will show the rate of traffic per second, as well as the total traffic on the subinterface. This can be used to compare the traffic on different subinterfaces.
Finally, the last step is to use the \show traffic statistics\ command to view the traffic statistics. This command will show the number of packets sent and received, as well as the total number of bytes sent and received. This can be used to identify any anomalies in the traffic.
Monitoring traffic on subinterfaces is an important part of maintaining a secure network. It allows an IT administrator to identify any anomalies in the traffic and take steps to address them. By configuring the VLANs and subinterfaces, enabling traffic monitoring, and viewing the traffic statistics, an IT administrator can ensure that their network is secure and running optimally.