I have an 871W.\n\nI have a switch supporting:\n\nVLAN 10 - general machines (10.0.*.*)\nVLAN 20 - special machines (10.1.*.*)\n\nThis is connected to an 871W router via a trunk line.\n\nThe router has:\n\n -FastEthernet 0 defined as trunk line to the switch.\n\n -Vlan 10 defined as bridge-group 10, no ip address\n\n -BVI 10 defined with 10.0.0.2 (router's ip address)\n\n -Dialer-1 defined to link to the ISP via PPPoE\n\n -FastEthernet4 defined as the PPPoE output to a modem.\n\n -DotRadio interfaces defined as bridge-group 10 and vlan 10.\n\nand I have a :\n bridge irb\n bridge 10 protocol ieee\n bridge 10 route ip\n\nSo far, the router works fine to connect the wi-fi to the lan, and both\nto the internet, all within the confines of Vlan-10.\n\n\nI would like the router to be given a new 10.1.0.2 interface and be able\nto route packets between the 10.0 subnet (VLAN 10) and 10.1 subnet (vlan\n20) with each vlan served by the same trunk line.\n\ngoal: allow a machine in vlan 10 to talk to a machine on vlan 20 (I used\nto use switchport multi on the switch to allow specific machines such\naccess, and all machines were in same subnet).\n\nAka: packets from 10.0.0.20 travel as vlan 10 from the switch , via the\ntrunk line to the router, then get routed to 10.1.0.5, encapsulated as\nVLAN 20 traveling back through the trunk line to the destination on the\nswitch.\n\n\nHow do I do that ?\n-what interface gets the 10.1.0.2 IP ? a new BVI one ? the vlan 20 ?\n-how do I link this interface so that packets get routed at IP level ?\n\nOr is the only way to use a separate ethernet interface, give that the\nip address ? And in such a case, is the routing automatic or must I tie\nthe interface to the bridge group, or must I add specific "IP route"\ncommands ?\n\nI note that the "Dialer 1" interface has no explicit attachement to the\nbridge group or VLAN. I assume that the router automatically makes all\ndialer interfaces available for routing.\n\n\n\nI've seen examples where non-trunk ethernet interfaces were each given\nIPs in different subnets, but have not seen instances of trunk lines\nsupporting different subnets in different vlans.