Service Manual

• Members can have different Link MTU values. Tagged members must have a
link MTU 4 bytes higher than untagged members to account for the packet tag.
• The VLAN link MTU and IP MTU must be less than or equal to the link MTU and
IP MTU values configured on the VLAN members. For example, the VLAN
contains tagged members with Link MTU of 1522 and IP MTU of 1500 and
untagged members with Link MTU of 1518 and IP MTU of 1500. The VLAN’s Link
MTU cannot be higher than 1518 bytes and its IP MTU cannot be higher than
1500 bytes.
The following describes the difference between Link MTU and IP MTU.
Layer 2 Overhead Difference between Link MTU and IP MTU
Ethernet
(untagged)
18 bytes
VLAN Tag Tag 22 bytes
Untagged Packet
with VLAN-Stack
Header
22 bytes
Tagged Packet
with VLAN-Stack
Header
26 bytes
Related
Commands
mtu — sets the link MTU for an Ethernet interface.
ip name-server
Enter up to six IPv4 addresses of name servers. The order you enter the addresses determines the order
of their use.
Syntax
ip name-server ipv4-address [ipv4-address2...ipv4-address6]
To remove a name server, use the no ip name-server ip-address command.
Parameters
ipv4-address Enter the IPv4 address, in dotted decimal format, of the
name server to be used.
ipv4-address2...
ipv4-address6
(OPTIONAL) Enter up five more IPv4 addresses, in dotted
decimal format, of name servers to be used. Separate the
addresses with a space.
Defaults No name servers are configured.
Command Modes CONFIGURATION
912
IPv4 Routing