To share what I've learned !

Reference Comparing , Designing and Deploying VPNs chap - 02 : L2TPv3 is the enhanced version of L2TPv2 protocol. Mikrotik uses L2TPv2 i suppose but it offer another similar tunneling mechanism as EOIP. L2TPv3 in cisco provides Pseudo-wire services to the customer. L2TPv3 only require the IP connectivity between peers but it can transport Ethernet, 802.1Q , HDLC, PPP framerelay etc. Advantage over MPLS is the customer having the full control of their routing domain. L2TP depolyment methods having 3 topologies LAC - LNS , LNS - LNS , LAC - LAC Following Diagram explain simple LAC - LAC L2TPv3 setup. It uses two types of messages: control connection messages - used for signaling between LCEs session data messages - Used to transport layer 2 protocols and connections Data channel Message Header having Session ID & cookie to correctly associate with the tunnel Deploying dynamic Pseudowires session 1) configure CEF - Its default in IOSs now. 2) configure a loopback in...

Basically i had a packet capture file where i need to check the ICMP sequence number to check any packet drops. going each packet one by one and finding out the sequence number is a tedious job. So i was looking to find a way to add another column to display the icmp sequence number. Its quite easy 1) Go to Edit -> Preference 2) Add a new column and select the field type as custom and give the filter as icmp.seq 3) You can see following result . According to our requirement we can modify the field type.