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.
C-Series, E-Series, S-Series, Z-Series, S4810
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
Command History
Version 8.3.11.1 Introduced on the Z9000.
Version 8.3.7.0 Introduced on the S4810.
Version 8.1.1.0 Introduced on the E-Series ExaScale.
Version 7.6.1.0 Introduced on the S-Series.
Version 7.5.1.0 Introduced on the C-Series.
pre-Version 
6.1.1.0
Introduced on the E-Series.
Usage 
Information
FTOS does not support sending DNS queries over a VLAN. DNS queries are sent out on all 
other interfaces, including the Management port.
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