Monthly Archives: March 2010
Export and Import map
We can selectively import/export vpnv4 prefix to a VRF using import/export map. Below is the summary; Export Map; We can match a prefix using access-list and set the extended community RT to a specific value. The Export RTs configured on the VRF … Continue reading
MPLS VPN Notes
MPLS VPN Terminologies; CE router- Router in Customer network (C-network) which peers with service provider edge(PE- router) in Provider network (P-network) P-routers are completely unaware of VPN. Only edge-routers(PE) are aware.
Few MPLS timers
Below are some default timer values associated with MPLS. LDP Discovery hello interval 5 secs. Can be changed by “mpls ldp discovery hello x” LDP neighbor hold interval 15 sec. Can be changed by “mpls ldp discovery hello holdtime x” LDP session … Continue reading
MPLS Reserved Labels
RFC 3032 mentions about reserved labels whose range is from 0-15. Label-0:” Explicit IPv4 Null Label”; Purpose of this label is same as “implicit Null Label” mentioned below.
VPLS
VPLS – Virtual Private LAN Service (VPWS – wire) For Seamless integration of networks like HDLC, Ethernet, FR, ATM. The service provider network act as a L2 virtual switch. VSI (Virtual switching Identifier) is used for packet switching. VSI forwarding information has data about … Continue reading
BGP scan-time
By default, BGP performs an internal check(scans) the next-hop reachability of BGP routes every 15 sec. we can change it using “bgp scan-time”. same command with “import” options can be used to detect changes in vpnc4 routes and hence result … Continue reading
MPLS Label Parameters
MPLS Label paramters; LABEL SPACE; Per-interface label space Labels are assigned unique to specific input interface Same labels can be used on another input interface with different meaning. Label forwarding based on incoming interface and label. Hence, label spoofing can … Continue reading
LC-ATM and VC Merge
Below are some points about LC(Label Controlled)-ATM interfaces and VC Merge; In cell-mode MPLS networks, the label is encoded as the VPI/VCI field from the ATM header. The number of virtual circuits supported by router and switch hardware is severely limited • Conclusion: … Continue reading
Internet Protocols 