Hi all, Consider a special scenario....
4 x 3560, has link physically connected. Cat1 port 23 <--> Cat2 port 23 Cat1 port 24 <--> Cat2 port 24 Cat2 port 19 <--> Cat3 port 19 Cat3 port 23 <--> Cat4 port 23 Cat3 port 24 <--> Cat4 port 24 And configure trunk link as follows: Cat1 <--> Cat2 <--> Cat3 <--> Cat4 when Cat2 and Cat3 communicate using routed ports, it cannot get thru... Cat2 .....Cat1 <--> Cat2 <--> Cat3 <--> Cat4 ..... Cat3 ..... means routed port (Cat2, Cat3 Routed port, Cat1, Cat4 access port) <--> means trunk link. So, what is the reason, why it cannot work? Configuration as follows Cat1: vtp mode transp vlan 123 int f0/23 desc trunk Cat1 to Cat2 switchport trunk enc dot1q switchport mode trunk no shut int f0/24 desc access port attach Cat2 switchport mode access switchport access vlan 123 no shut Cat2: vtp mode transp vlan 123 int f0/23 desc trunk Cat2 to Cat1 switchport trunk enc dot1q switchport mode trunk no shut int f0/24 desc routed port to Cat1 no switchport ip addr 1.1.1.2 255.255.255.0 no shut int f0/19 desc trunk Cat2 to Cat3 switchport trunk enc dot1q switchport mode trunk no shut Cat3: vtp mode transp vlan 123 int f0/19 desc trunk Cat3 to Cat2 switchport trunk enc dot1q switchport mode trunk no shut int f0/23 desc trunk Cat3 to Cat4 switchport trunk enc dot1q switchport mode trunk no shut int f0/24 desc routed port to Cat4 no switchport ip addr 1.1.1.3 255.255.255.0 no shut Cat4: vtp mode transp vlan 123 int f0/23 desc trunk Cat4 to Cat3 switchport trunk enc dot1q switchport mode trunk no shut int f0/24 desc access port attach Cat3 switchport mode access switchport access vlan 123 no shut
