|
本帖最后由 兲笙吥丶倫尐 于 2012-8-14 19:17 编辑
首先,颠覆了大家一个概念——VLAN间通信,不一定要走3层(这里主要是用来验证“打标签”这个过程在哪里执行)
先明确几点:
——交换机对于目的地址未知的帧,是把它泛洪到除收到该帧的接口的其他和收到帧的接口属于同一个VLAN的接口(有点绕,仔细看看)。
——为了区分不同VLAN的数据帧,在Trunk的入接口把帧打上标签。到出接口在去掉——交换机已经通过去掉tag这个过程知道帧属于那个VLAN了。
——这里2台主机要在相同子网里——原因很简单。不在相同子网里,主机根据IP地址发现不是同一个网络,会是一个对网管的ARP请求。自然没人回答。
而如果是同子网就简单了,数据帧是广播帧,在本VLAN的除接收口外的接口泛洪。
sw0:
Switch#sh vlan
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Fa1/1, Fa2/1, Fa4/1, Fa5/1
20 V20 active Fa0/1, Fa3/1
1002 fddi-default active
1003 token-ring-default active
1004 fddinet-default active
1005 trnet-default active
VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1 enet 100001 1500 - - - - - 0 0
20 enet 100020 1500 - - - - - 0 0
1002 enet 101002 1500 - - - - - 0 0
1003 enet 101003 1500 - - - - - 0 0
1004 enet 101004 1500 - - - - - 0 0
1005 enet 101005 1500 - - - - - 0 0
sw1:
Switch#sh vlan
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Fa1/1, Fa2/1, Fa4/1, Fa5/1
10 V10 active Fa0/1, Fa3/1
1002 fddi-default active
1003 token-ring-default active
1004 fddinet-default active
1005 trnet-default active
VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1 enet 100001 1500 - - - - - 0 0
10 enet 100010 1500 - - - - - 0 0
1002 enet 101002 1500 - - - - - 0 0
1003 enet 101003 1500 - - - - - 0 0
1004 enet 101004 1500 - - - - - 0 0
1005 enet 101005 1500 - - - - - 0 0
Pc2:
PC>ipconfig
IP Address......................: 192.168.1.1
Subnet Mask.....................: 255.255.255.0
Default Gateway.................: 0.0.0.0
PC>ping 192.168.1.2
Pinging 192.168.1.2 with 32 bytes of data:
Reply ** 192.168.1.2: bytes=32 time=93ms TTL=128
Reply ** 192.168.1.2: bytes=32 time=94ms TTL=128
Reply ** 192.168.1.2: bytes=32 time=78ms TTL=128
Reply ** 192.168.1.2: bytes=32 time=94ms TTL=128
Ping statistics for 192.168.1.2:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 78ms, Maximum = 94ms, Average = 89ms
PC1:
PC>ipconfig
IP Address......................: 192.168.1.2
Subnet Mask.....................: 255.255.255.0
Default Gateway.................: 0.0.0.0
PC>ping 192.168.1.1
Pinging 192.168.1.1 with 32 bytes of data:
Reply ** 192.168.1.1: bytes=32 time=93ms TTL=128
Reply ** 192.168.1.1: bytes=32 time=94ms TTL=128
Reply ** 192.168.1.1: bytes=32 time=93ms TTL=128
Reply ** 192.168.1.1: bytes=32 time=94ms TTL=128
Ping statistics for 192.168.1.1:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 93ms, Maximum = 94ms, Average = 93ms
这是看到别人的贴转过来的,有什么问题的话大家可以讨论一下
|
|