Specifications

ESRP Concepts
ExtremeWare XOS 11.0 Concepts Guide 231
To participate in ESRP, the following must be true:
• A VLAN can belong to only one ESRP domain.
• The IP address for the VLANs participating in an ESRP domain must be identical.
• All switches in the ESRP network must use the same election algorithm, otherwise loss of
connectivity, broadcast storms, or other unpredictable behavior may occur.
• If you have an untagged master VLAN, you must specify an ESRP domain ID. The domain ID must
be identical on all switches participating in ESRP for that particular domain.
• If you have a tagged master VLAN, ESRP uses the 802.1Q tag (VLANid) of the master VLAN for the
ESRP domain ID. If you do not use the VLANid as the domain ID, you must specify a different
domain ID. As previously described, the domain ID must be identical on all switches participating in
ESRP for that particular domain.
ESRP-Aware Switches
Extreme Networks switches that are not running ESRP but are connected on a network that has other
Extreme Networks switches running ESRP are ESRP-aware. When ESRP-aware switches are attached to
ESRP-enabled switches, the ESRP-aware switches reliably perform failover and failback scenarios in the
prescribed recovery times.
No configuration of this feature is necessary. However, you can improve the performance of the
ESRP-aware switch to forward packets and perform failover operations if you configure an ESRP
domain on an ESRP-aware switch. Use the
create esrp <esrpDomain> command to create an ESRP
domain. After you create the domain, do not enable it.
If Extreme Networks switches running ESRP are connected to Layer 2 switches that are manufactured
by third-party vendors, the failover times for traffic local to that segment may appear longer, depending
on the application involved and the FDB timer used by the other vendor’s Layer 2 switch. ESRP can be
used with Layer 2 switches from other vendors, but the recovery times vary.
The VLANs associated with the ports connecting an ESRP-aware switch to an ESRP-enabled switch
must be configured using an 802.1Q tag on the connecting port; or, if only a single VLAN is involved, as
untagged using the protocol filter
any. ESRP will not function correctly if the ESRP-aware switch
interconnection port is configured for a protocol-sensitive VLAN using untagged traffic. You can also
use port restart in this scenario. For more information about port restart, see “ESRP Port Restart” on
page 241.
To display ESRP-aware information, use the following command:
show esrp {<name>}
The display includes the group number and MAC address for the master of the group, as well as the
age of the information.
Standard and Extended ESRP
ESRP has two modes of operation: standard and extended. By default, ExtremeWare XOS operates in
extended mode. To configure a different mode of operation, use the following command:
configure esrp mode [extended | standard]
Standard mode is backward compatible with and supports the ESRP functionality of switches running
ExtremeWare. ESRP functionality available in extended mode is not applicable in standard mode. Use