Specifications

Configuring RADIUS Server Groups
18-6 Configuring Communication with RADIUS
Configuring RADIUS Server Groups
AservergroupisanamedgroupofuptofourRADIUSservers.BeforeyoucanuseaRADIUS
serverforauthentication,youmustfirstcreateaRADIUSservergroupandaddtheRADIUS
servertothatgroup.Youcanalsoarrangeloadbalancing,sothatauthenticationsarespreadout
among
serversinthegroup.Youmustdeclareallmembersofaservergroup,incontactorder,
whenyoucreatethegroup.
Oncethegroupisconfigured,youcanuseaservergroupnameastheAAAmethodwiththeset
authenticationandsetaccountingcommands.(SeeChapter 3,ConfiguringAAAfor

AdministrativeandLocalAccessandChapter 17,ConfiguringAAAforNetworkUsers.)
Subsequently,youcanchangethemembersofagrouporconfigureloadbalancing.
IfyouaddorremoveaRADIUSserverinaservergroup,alltheRADIUSdeadtimersforthat
servergroupareresettothe 
globaldefault.
Creating Server Groups
Tocreateaservergroup,youmustfirstconfiguretheRADIUSserverswiththeiraddressesand
anyoptionalparameters.AfterconfiguringRADIUSservers,typethefollowingcommand:
set server group group-name members server-name1 [server-name2] [server-name3]
[server-name4]
Example
TocreateaservergroupcalledshorebirdswiththeRADIUSserversheron,egret,andsandpiper,type
thefollowingcommands:
RBT-8100# set radius server egret address 192.168.253.1 key apple
RBT-8100# set radius server heron address 192.168.253.2 key pear
RBT-8100# set radius server sandpiper address 192.168.253.3 key plum
RBT-8100# set server group shorebirds members egret heron sandpiper
Inthisexample,arequesttoshorebirdsresultsintheRADIUSserversbeingcontactedintheorder
thattheyarelistedintheservergroupconfiguration,firstegret,thenheron,thensandpiper.Youcan
changetheRADIUSserversinservergroupsatanytime.(See“AddingMemberstoa
Server
Group”onpage 18‐7.)
Ordering Server Groups
Youcanconfigureuptofourmethodsforau thentication,authorization,andaccounting(AAA).
AAAmethodscanbethelocaldatabaseontheRoamAboutswitchand/oroneormoreRADIUS
servergroups.YousettheorderinwhichtheRoamAboutswitchattemptstheAAAmethodsby
theorderinwhichyouenter
themethodsinCLIcommands.
Inmostcases,ifthefirstmethodresultsinapassorfail,theevaluationisfinal.Ifthefirstmethod
doesnotrespondorresultsinanerror,theRoamAboutswitchtriesthesecondmethodandsoon.
Note: Any RADIUS servers that do not respond are marked dead (unavailable) for a period of time.
The unresponsive server is skipped over, as though it did not exist, during its dead time. Once the
dead time elapses, the server is again a candidate for receiving requests. To change the default
dead-time timer, use the set radius or set radius server command.