Specifications

RoamAbout Mobility System Software Configuration Guide 5-1
5
Configuring and Managing
IP Interfaces and Services
MTU Support
MobilitySystemSoftware(MSS)supportsstandardmaximumtransmissionunits(MTUs)of1514
bytesforstandardEthernetpacketsand1518bytesforEthernetpacketswithan802.1Qtag.MSS
doesnotsupportchangingoftheMTUthroughsoftwareconfiguration,andMSSdoesnotdopath
MTUdiscovery.
CommunicationbetweenRoamAboutsw itchesis
supportedoveranypath MTU,andtheMobility
DomainitselfcanrunovertheminimumIPpathMTU(PMTU).However,tunnelsbetweentwo
RoamAboutswitchesrequireapathMTUofatleast1384bytes.
ThisminimumMTUpathisrequiredbecauseEnterasysdevicesuseIPtunnelstotransportuser
traffic
betweenRoamAboutswitchesandtotransportusertrafficandcontroltrafficbetween
switchesandAPs.Encapsulationofthepacketsfortunnelingaddsanadditional44bytestothe
packetheaders,soMSSdoesfragmentandreassemblethepacketsifnecessarytofitwithinthe
supportedMTUs.However,MSSdoesnotsupport
defragmentationexceptatthereceivingendof
anIPtunnel,andonly toreassemblefragmentscreatedbyanotherEnterasysdevicefortunneling.
IfthepathMTUbetweenEnterasysdevicesislessthan1448bytes,adeviceinthepathmight
furtherfragmentordropatunneledpacket.Ifthepacket
isfurtherfragmented,thereceiving
RoamAboutSwitchwillnotbeabletoreassemblethefragments,andthepacketisdropped.
For information about... Refer to page...
MTU Support 5-1
Configuring and Managing IP Interfaces 5-2
Configuring the System IP Address 5-5
Configuring and Managing IP Routes 5-6
Managing the Management Services 5-9
Configuring and Managing DNS 5-16
Configuring and Managing Aliases 5-18
Configuring and Managing Time Parameters 5-20
Managing the ARP Table 5-25
Pinging Another Device 5-27
Logging In to a Remote Device 5-28
Tracing a Route 5-29
IP Interfaces and Services Configuration Scenario 5-30