Xrrp Support On Switch 5300Xl Series; Appendix H: Ospf Equal Cost Multipath - HP ProCurve 3500-24 Reference Manual

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XRRP support on Switch 5300xl series

Similar in concept to VRRP, the HP ProCurve XL Router Redundancy Protocol (XRRP) provides the equivalent
mechanism in the HP ProCurve Switch 5300xl series for backup functionality . Like VRRP, XRRP presents a virtual
router to the end-node connections whose IP and MAC address can transition from the master HP ProCurve
Switch 5300xl to the backup HP ProCurve Switch 5300xl in the event the master HP ProCurve Switch 5300xl
interface fails .
XRRP does not interoperate with VRRP but can coexist in a VRRP environment without interference .

Appendix H: OSPF Equal Cost Multipath

In Open Shortest Path First (OSPF), if different subnet destinations in a network are reachable through multiple
equal-cost paths, the router chooses a single path for each destination subnet . (A trunk is considered a path
even though a trunk consists of multiple links) .
With OSPF Equal Cost Multipath (OSPF-ECMP), routers support optional load-sharing across redundant paths
to the same subnet . All traffic for different hosts in the same subnet may go through a different next-hop router .
Multiple paths are balanced, based on destination IP address .
HP ProCurve's OSPF-ECMP feature is interoperable with OSPF-ECMP implementations from various vendors
including Cisco, 3Com, and Extreme . The HP ProCurve implementation supports up to four ECMP paths .
Figure A8.
The example shows that there are three equal-cost, next-hop paths from Router A to the destination subnets with
load-sharing across redundant paths . Router A can route packets based on destination IP address as follows:
Destination IP
10 . 1 . 1 . 1
10 . 1 . 1 .2
10 . 1 .2 .3
10 .32 . 1 . 1
10 .32 . 1 .2
10 .32 . 1 .3
Next hop
Router C
Router B
Router B
Router B
Router C
Router B