The 5300xl doesn't support VRRP, but it does implement HP's own XRRP (XL Router Redundancy Protocol) which is similar.
The major practical limitations in XRRP vs. VRRP are that
- XRRP allows only two devices to back up each other, whereas VRRP supports a maximum of 255 physical routers per virtual address;
- an XRRP failover causes all virtual addresses to fail over at the same time -- that is, if any one virtual router fails, all of the virtual routers will fail over to the backup device; in VRRP all virtual routers operate independently;
Also, there seem to be some implementation problems in XRRP. In particular, new IP interfaces won't work unless you disable and re-enable XRRP (at least on the 3400cl/6400cl series) globally on the switch. This only takes a few seconds, but during that time traffic on other XRRP-enabled subnets may be disrupted temporarily, since the XRRP virtual MAC address gets removed.
Since VRRP instances for different subnets operate independently from one another, making changes to one router interface typically has no effect on others.
XRRP is explained in detail in the Advanced Traffic Management Guide for the 5300xl series:
http://www.hp.com/rnd/support/manuals/5300xl.htm-leok