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.

out of band management is critical for the network operation. when searching solution for console access through rs232 and 3G i came across Mikrotik serial connection option. I haven't tested the 3G setup yet but quite impressive options available in 79$ Mikrotik router for RS232 access: 1st have to set the baud-rate and similar settings : [admin@Console_Tik] > port export # jan/02/1970 00:32:05 by RouterOS 5.5 # software id = WE49-11I9 # /port set 0 baud-rate=9600 data-bits=8 flow-control=none name=serial0 parity=none \ stop-bits=1 /port firmware set directory=firmware [admin@Console_Tik] > 2nd if we are using for console access we need to disable the console port option on mikrotik as follows : [admin@Console_Tik] > system console print Flags: X - disabled, U - used, F - free # PORT TERM 0 X serial0 vt102 From mikrotik we can directly access the co...

when it comes to mpls + vrf we can observe some lengthly commands.. R3#show bgp vpnv4 unicast vrf CusA BGP table version is 7, local router ID is 192.168.254.3 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path Route Distinguisher: 65001:100 (default for vrf CusA) *> 192.168.200.0 192.168.100.1 0 0 65100 i *>i192.168.210.0 192.168.254.8 0 100 0 65101 i how to shorten these commands as usual we can use aliases eg: alias exec shbgpvrf show bgp vpnv4 unicast vrf R3#shbgpvrf CusA BGP table version is 7, local router ID is 192.168.254.3 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric L...

This is the lab prepared using the L2IOU (http://tinyurl.com/69j77ju ) NETMAP : 1:0/0 3:0/0 1:0/1 4:0/0 2:0/0 3:0/1 2:0/1 4:0/1 3:0/2 5:0/0 4:0/2 5:0/1 5:0/3 6:0/0 5:0/2 7:0/1 6:0/1 7:0/0 7:0/2 8:0/0 7:0/3 9:0/0 8:0/1 10:0/0 9:0/1 11:0/0 root@box:/home/tc# cat labstart_mpls #!/bin/sh if [ "`pgrep i86bi`" ] then echo "" echo "" echo "The lab is already loaded" echo "" echo "" else echo "" echo "" echo please wait for the Lab to be loaded.. echo "" ./wrapper -m ./i86bi_linuxl2-upk9-ms.M -p 2001 -- -c configs/R1.cfg -e1 -s0 1 > /dev/null 2>&1 & sleep 5 echo R1 loaded ./wrapper -m ./i86bi_linuxl2-upk9-ms.M -p 2002 -- -c configs/R2.cfg -e1 -s0 2 > /dev/null 2>&1 & sleep 5 echo R2 loaded ./wrapper -m ./i86bi_linuxl2-upk9-ms.M -p 2003 -- -c configs/R3.cfg -e1 -s0 3 > /dev/null 2>&1 & sleep 5 echo R3 loaded ./wrapper -m ./i86bi_...

according to my experience we can't but similar functionalities given by Local AS option . It enables to act one AS for some of the neighbors and another AS for other neighbors R2 connects to R1 using remote as 100 , but the R1 using remote-as as 2 rather than 300 R2# router bgp 300 no synchronization bgp log-neighbor-changes network 200.200.200.0 neighbor 192.168.100.1 remote-as 100 neighbor 192.168.100.1 local-as 2 R1#router bgp 100 no synchronization bgp log-neighbor-changes neighbor 192.168.100.2 remote-as 2 no auto-summary but when the route injected it shows originated AS as 300 R1#show ip bgp BGP table version is 2, local router ID is 192.168.100.1 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 200.200.200.0 192.168.100.2 0 0 2 300 i with no-p...

this lab is directly taken from BGP Design & Implementation Chap 4. GNS3 configurations attached below. Summary - In the boarder router if the summary route injected as follows aggregate-address 172.16.0.0 255.255.0.0 as-set summary-only downwards the originality of the prefix may be lost therefore to specify the best exist path we can regenerate the path we use inject path . bgp inject-map Map1 exist-map Map2 Map1 injects the path Map2 checks whether path is available , it at least two match statements one is route-source & aggregate prefix. Whether u can inject weird prefix other than aggregate .. (eg aggregate is 172.16.0.0/16 but if you try to inject 10.0.0.0/24 ???) As usual you can't :) following is the attached diagram R5 Relevant configuration. router bgp 100 no synchronization bgp log-neighbor-changes bgp inject-map AS200-Specific exist-map AS200-aggregate neighbor 192.168.12.2 remote-as 100 neighbor 192.168.12.2 send-community neighbor 192.168.23....