One of the keystones to success in the SP Lab Exam is verification. Now this is obviously key to all tracks but is particularly complex in SP.
With the RS exam there are 4 ways to verify connectivity – ping, traceroute, routing table lookup and TCL Scripting [extended version of ping] where we put together a TCL Script using the foreach functionality – specify the various IP ranges used during the exam and execute the perl script on the routers. It has been covered in various other posts so here’s a link to NMC’s[or Cisco’s] TCL document -> http://www.netmasterclass.net/site/articles/CISCO%20IOS%20TCL%20and%20RCMD%20testing%20and%20troubleshooting%20scripting.pdf
Note that for the for the 3550’s, they do not support TCL rather use macro’s so in config mode type…
macro name ICMP
do ping 18.104.22.168
do ping 22.214.171.124
do ping 126.96.36.199
do ping 188.8.131.52
However we use the address-family concept in SP and as a result this technique is only valid for L2 & L3 addresses not associated with address-families. As a result we need to place various appendages to our verification commands. Concentrating on the MPLS VPN world we use…
“show ip bgp vpn all summary” command to check the MP-BGP establishment status
“show ip vrf detail” command to verify the import and export route targets.
“ping vrf <vrf> <ip address> source <source ip>” to ping ip addresses not in standard routing table
“sh ip bgp vpn all summary”
Lists all of the MP-BGP and CE peers.
“sh ip bgp vpn all”
Lists all of the VPN prefixes advertised and received by the router.
“sh ip bgp vpn vrf <vrf> summary”
Similar to the first command, but for a specific VRF.
“sh ip bgp vpn vrf <vrf>”
Lists all of the VPN prefixes received in a specific VRF.
“sh ip bgp vpn vrf <vrf> labels”
Lists labels for the VPN prefixes in a VRF.
“sh mpls forwarding”
Shows all LFIB entries (VPN, non-VPN, TE, and so on).
“sh mpls forwarding | inc <prefix>”
Shows whether the prefix is present in the LFIB or not.
“sh mpls forwarding vrf <vrf> <prefix>”
Shows LFIB lookup based on a VPN prefix.
“sh mpls forwarding label <label>”
Shows LFIB lookup based on an incoming label.
This also extends to Multicast wher you need to amend the commands such as sh ip pim vrf <vrf> int, etc.
As you can see the verification in the MPLS VPN portion of the lab will require a good deal of time and hence perhaps why Cisco perform so much pre-config on this exam.