This shows you the differences between two versions of the page.
Both sides previous revision Previous revision Next revision | Previous revision | ||
icnd1:trunking_and_vlans [2024/04/26 22:42] 114.119.145.194 old revision restored (2023/10/27 18:45) |
icnd1:trunking_and_vlans [2024/05/14 01:42] (current) 114.119.145.194 old revision restored (2023/10/06 01:02) |
||
---|---|---|---|
Line 1: | Line 1: | ||
====== Trunking and VLANs ====== | ====== Trunking and VLANs ====== | ||
- | VLANs create separate broadcast domains and isolates traffic to it's own VLAN. Switches will not forward traffic out ports that aren't in their VLAN. Basically, traffic from VLAN 10 cannot reach VLAN 20. | + | VLANs create separate broadcast domains and isolates traffic to it's own VLAN. Switches will not forward traffic out ports that aren't in their VLAN. Basically, traffic from VLAN 10 cannot reach VLAN 20. Makes grouping traffic pretty easy. For example you may group ACCOUNTING and IT machines into different VLANs. |
- | Trunking | + | Trunking |
- | ===== Notes ===== | ||
- | ISL is largely unsupported. 802.1Q is the IEEE standard and most adopted. | ||
- | < | ||
- | |||
- | 802.1Q: | ||
- | * -Frames are tagged with a VLAN ID Field | ||
- | * Both ISL and .1Q tag a 12bit VLAN Field | ||
- | * -Untagged frames are sent to the NATIVE VLAN on the receiving port. | ||
- | * -It's best practice to have the same NATIVE VLANs set on each side to avoid inconsistencies. | ||
===== Configuration ===== | ===== Configuration ===== | ||
Line 96: | Line 87: | ||
</ | </ | ||
- | |||
- | ===== Command reference ===== | ||
- | ---- | ||
- | < | ||
- | Switch(config-if)# | ||
- | access | ||
- | dynamic | ||
- | trunk Set trunking mode to TRUNK unconditionally | ||
- | | ||
- | Switch(config-if)# | ||
- | auto Set trunking mode dynamic negotiation parameter to AUTO | ||
- | desirable | ||
- | </ | ||
- | < | ||
- | Switch(config-if)# | ||
- | |||
- | Switch#show interfaces trunk | ||
- | Port Mode | ||
- | Fa0/ | ||
- | Gig0/ | ||
- | |||
- | Port Vlans allowed on trunk | ||
- | Fa0/ | ||
- | Gig0/ | ||
- | |||
- | Port Vlans allowed and active in management domain | ||
- | Fa0/ | ||
- | Gig0/ | ||
- | |||
- | Port Vlans in spanning tree forwarding state and not pruned | ||
- | Fa0/ | ||
- | Gig0/ | ||
- | </ | ||
- | < | ||
- | Switch#show vlan brief | ||
- | |||
- | VLAN Name | ||
- | ---- -------------------------------- --------- ------------------------------- | ||
- | 1 default | ||
- | Fa0/5, Fa0/6, Fa0/7, Fa0/8 | ||
- | Fa0/9, Fa0/10, Fa0/11, Fa0/12 | ||
- | Fa0/17, Fa0/18, Fa0/19, Fa0/20 | ||
- | Fa0/21, Fa0/22, Fa0/23, Gig0/2 | ||
- | 2 VLAN0002 | ||
- | 3 VLAN0003 | ||
- | 900 ENG active | ||
- | 990 TEST | ||
- | 1002 fddi-default | ||
- | 1003 token-ring-default | ||
- | 1004 fddinet-default | ||
- | 1005 trnet-default |