Monitoring VLAN Subinterfaces

Purpose

Display configuration and status information for a specified VLAN subinterface or for all VLAN subinterfaces configured on the router. You can use the summary keyword to display only the counts of all VLAN subinterfaces and VLAN major interfaces configured on the router. You can use the mac-address keyword to display information about the VLAN subinterfaces that were configured with unique MAC addresses. You can use the vlan or svlan keywords to display information about specific S-VLAN IDs or VLAN IDs.

Action

To display full status and configuration information for all VLAN subinterfaces configured on the router:

host1#show vlan subinterface
    Interface      Status  MTU  Svlan Id Vlan Id Ethertype Type
----------------- -------- ---- -------- ------ --------- -------
ATM 3/0.1.2         Up     1522 ----     11      ----      Static
ATM 3/0.1.3         Up     1522 ----     12      ----      Static
ATM 3/1.1.1         Up     1522 ----     13      ----      Static
ATM 3/1.1.2         Up     1522 ----     14      ----      Static
ATM 3/2.1.1         Down   1526 4        255     0x9100    Static   
FastEthernet 4/5.1  Up      1522 ----     1       ----      Dynamic
6 vlan subinterfaces found

To display full status and configuration information for the specified VLAN subinterface:

host1#show vlan subinterface fastEthernet 0/0.1
    Interface       Status  MTU  Svlan Id Vlan Id Ethertype Type
------------------- ------ ---- -------- ------ --------- -------
FastEthernet 0/0.1    Up    1526    1      0    0x9100    Static
                                                                               
In: Bytes 39256, Packets 612
   Multicast 0, Broadcast 0
   Errors 0, Discards 0
  Out: Bytes 4538652, Packets 70911
   Multicast 0, Broadcast 70296
   Errors 0, Discards 0
ARP Statistics:
  In: ARP requests 0, ARP responses 0
   Errors 0, Discards 0
  Out: ARP requests 0, ARP responses 0
   Errors 0, Discards 0

To display only brief summary information for all VLAN subinterfaces configured on the router:

host1#show vlan subinterface summary
Total VLAN interfaces: 6 subinterfaces, 3 major interfaces

To display full status and configuration information for all VLAN subinterfaces configured with a unique MAC address:

host1#show vlan subinterface mac-address
     Interface          Svlan Id Vlan Id   MAC Address
----------------------  -------- --------  --------------
FastEthernet 4/0.25       ----     25    0090.dfad.2abd
FastEthernet 4/0.10050     1       50    0090.adad.0abd
2 vlan subinterfaces found

To display full status and configuration information for a VLAN subinterface on a LAG bundle:

host1#show vlan subinterface lag boston.1
    Interface     Status  MTU  Svlan Id Vlan Id Ethertype  Type 
---------------- -------- ---- -------- -------- --------- ------
lag boston.1       Up     1522 ----     1        ----      Static

To display full status and configuration information for the specified S-VLAN ID:

host1#show vlan subinterface svlan 100 53
      Interface         Status  MTU  Svlan Id Vlan Id Ethertype  Type
------------------------ ------ ---- -------- -------- --------- -------
FastEthernet 0/0.1        Up    1526 100      53      0x9100    Static
FastEthernet 4/6.1        Up    1526 100      53      0x9100    Dynamic
2 vlan subinterfaces found

Meaning

Table 10 lists the show vlan subinterface command output fields.

Table 10: show vlan subinterface Output Fields

Field Name	Field Description
Interface	Type and specifier of the VLAN subinterface
Status	Status of the VLAN subinterface: up, down, dormant, lowerLayerDown, absent
MTU	Maximum allowable size (in bytes) of the maximum transmission unit (MTU) for the VLAN subinterface
Svlan Id	S-VLAN ID value, if configured
Vlan Id	VLAN ID value for the VLAN subinterface
Ethertype	S-VLAN Ethertype value, if configured
Type	Type of VLAN subinterface: Static—VLAN or S-VLAN subinterface was configured statically Dynamic—VLAN or S-VLAN subinterface was configured dynamically
In	Analysis of inbound traffic on this interface: Bytes—Number of bytes received on the VLAN or S-VLAN subinterface Packets—Sum of all unicast, broadcast, and multicast packets received on the VLAN or S-VLAN subinterface Multicast—Number of multicast packets received on the VLAN or S-VLAN subinterface Broadcast—Number of broadcast packets received on the VLAN or S-VLAN subinterface Errors—Total number of errors in all received packets; some packets might contain more than one error Discards—Total number of discarded incoming packets
Out	Analysis of outbound traffic on this interface: Bytes—Number of bytes sent on the VLAN or S-VLAN subinterface Packets—Number of packets sent on the VLAN or S-VLAN subinterface Multicast—Number of multicast packets received on the VLAN or S-VLAN subinterface Broadcast—Number of broadcast packets received on the VLAN or S-VLAN subinterface Errors—Total number of errors in all transmitted packets; some packets might contain more than one error Discards—Total number of discarded outgoing packets
ARP Statistics	Analysis of ARP traffic on this interface; In fields are for traffic received on the interface and Out fields are for traffic sent on the interface ARP requests—Number of ARP requests ARP responses—Number of ARP responses Errors—Total number of errors in all ARP packets Discards—Total number of discarded ARP packets
Total VLAN interfaces	Total numbers of VLAN subinterfaces and VLAN major interfaces configured on the router; this is the only field that appears when you specify the summary keyword

Monitoring VLAN Subinterfaces

Purpose

Action

Meaning

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