Configuring 4-ESW or 9-ESW HWIC - help please

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You need VLANs. Configure VLANs (or one VLAN if thats all you want). The 9-ESW is just like a Cisco 2-layer switch .1q trunked back into the router sandwiched together.

Thanks for the advice. Configuration is now: ! interface FastEthernet0/1 no ip address ip pim sparse-dense-mode ip nat inside ip virtual-reassembly duplex auto speed auto ! interface FastEthernet0/1/0 switchport mode trunk ! interface FastEthernet0/1/1 ! interface FastEthernet0/1/2 ! interface FastEthernet0/1/3 ! interface FastEthernet0/1/4 ! interface FastEthernet0/1/5 ! interface FastEthernet0/1/6 ! interface FastEthernet0/1/7 ! interface FastEthernet0/1/8 ! interface Vlan1 ip address 192.168.2.1 255.255.255.0 !

We have removed the IP address from the 0/1 interface and created one VLAN instance, Vlan1, and put the IP address on that. All Fe0/1/x now belong to this default Vlan1 (by default)

I don't understand " .1q trunked back " above. I have added switchport mode trunk against the first switchport 0/1/0 Is this necessary to aggregate together all the other ports and trunk back to 0/1, or should this line be deleted ?.

Should all this: ip pim sparse-dense-mode ip nat inside ip virtual-reassembly duplex auto speed auto be moved to under interface Vlan1 or put under each interface FastEthernet0/1/x ?

I want a single LAN with multiple ethernet devices connected, similar to having an external 8 port expansion hub plugged into interface

0/1. LAN = 192.168.2.0 / 255.255.255.0 with the router IP set to 192.168.2.1

Best regards, Eric

Suggest not using VLAN 1 for a variety of reasons

config t

no int vlan 1

int vlan 10 no ip proxy-arp no ip directed-broadcast ip address 192.168.2.1 255.255.255.0

! try using interface range command, otherwise config each of the switch ports individually

int range fa 0/1/0 - 8 switchport mode access switchport access vlan 10

no shut exit

end

wri mem

VLAN 10 will be the inside interface for NAT

Thanks Merv,

We have a second 2811 router for another site, which will have the same configuration, but with LAN 192.168.4.0 255.255.255.0 Each site is connected locally to the internet with a public IP address using its Fe0/0 interface, for the main public internet traffic flow. The sites are linked with a GRE tunnel, which is working OK. The GRE tunnel is for a limited amount of unicast, multicast and broadcast hardware management communication packets between all the LAN devices at all the sites. This illustration diagram may help

Will the choice of Vlan1 or Vlan10 affect this ? I am concerned that introducing any "VLAN" rather than then a plain "LAN" using the Fe0/1 interface alone, will reduce the layer 3 functionality. Would choice Vlan1 or 10 affect the Level3 multicast routing functionality ? I don't need more than one LAN at each site, so consideration of inter-VLAN non-Level3 functionality does not arise (I hope !).

The objective is just to use the 9-ESW HWIC instead of a separate 8 port expansion hub or switch plugged into interface Fe0/1.

Anyone may send longer replies direct to me at snipped-for-privacy@satsig.net if it is more convenient. I don't want to take up too much space here. This if the first time I have had a Cisco router and your comments and suggestions are gratefully received.

Best regards, Eric.

VLAN numbering will be local to the router unless traffic is carried across a 802.1Q trunk. If traffic is trunked the VLAN numbered is inserted into each packet.

If traffic is routed out of a box the the VLAN numbers would be of local significant only.

If you post the complete configs then it will be possible to comment on their content.

As always very insightful comments from Merv.

There is one thing that you should be aware of:-

interface FastEthernet0/1 no ip address ! unnecessary stuff removed duplex auto speed auto ! interface FastEthernet0/1/0 ! switchport mode trunk ! remove this too ! interface FastEthernet0/1/1 ! interface FastEthernet0/1/2 ! interface FastEthernet0/1/3 ! interface FastEthernet0/1/4 ! interface FastEthernet0/1/5 ! interface FastEthernet0/1/6 ! interface FastEthernet0/1/7 ! interface FastEthernet0/1/8 ! interface Vlan1 ip address 192.168.2.1 255.255.255.0 ! ip nat inside ! < -- Put this here if you need it,

The above config is OK

HOWEVER:-

The hardware switch (module) will do bridging between all fa0/1/0-8 but software bridging will be required to fa 0/1.

Worth avoiding if you can. At least use Fa 0/1 on something that does not do too much L2 traffic.

Re-casting avoiding VLAN 1

conf t

vlan 10 name This-n-that ! really just a label/comment

interface FastEthernet0/1 no ip address ! unnecessary stuff removed switchport mode access switchport access vlan 10 duplex auto speed auto ! interface FastEthernet0/1/0 switchport mode access switchport access vlan 10 spanning-tree portfast ! < -- if you have PC's or servers connected.

! interface range FastEthernet0/1/1 - 8 ! < -- another way to express the rest switchport mode access switchport access vlan 10 spanning-tree portfast ! < -- if you have PC's or servers connected. ! interface Vlan10 ip address 192.168.2.1 255.255.255.0 ! ip nat inside ! < -- Put this here if you need it,

end

As always very insightful comments from Merv.

There is one thing that you should be aware of:-

interface FastEthernet0/1 no ip address ! unnecessary stuff removed duplex auto speed auto ! interface FastEthernet0/1/0 ! switchport mode trunk ! remove this too ! interface FastEthernet0/1/1 ! interface FastEthernet0/1/2 ! interface FastEthernet0/1/3 ! interface FastEthernet0/1/4 ! interface FastEthernet0/1/5 ! interface FastEthernet0/1/6 ! interface FastEthernet0/1/7 ! interface FastEthernet0/1/8 ! interface Vlan1 ip address 192.168.2.1 255.255.255.0 ! ip nat inside ! < -- Put this here if you need it,

The above config is OK

HOWEVER:-

The hardware switch (module) will do bridging between all fa0/1/0-8 but software bridging will be required to fa 0/1.

Worth avoiding if you can. At least use Fa 0/1 on something that does not do too much L2 traffic.

Re-casting avoiding VLAN 1

conf t

vlan 10 name This-n-that ! really just a label/comment

interface FastEthernet0/1 no ip address ! unnecessary stuff removed switchport mode access switchport access vlan 10 duplex auto speed auto ! interface FastEthernet0/1/0 switchport mode access switchport access vlan 10 spanning-tree portfast ! < -- if you have PC's or servers connected.

! interface range FastEthernet0/1/1 - 8 ! < -- another way to express the rest switchport mode access switchport access vlan 10 spanning-tree portfast ! < -- if you have PC's or servers connected. ! interface Vlan10 ip address 192.168.2.1 255.255.255.0 ! ip nat inside ! < -- Put this here if you need it,

end