And additionally here are the detailed port configs on the switch end: hq>show interface Gi1/0/3 switchport Name: Gi1/0/3 Switchport: Enabled Administrative Mode: trunk Operational Mode: trunk Administrative Trunking Encapsulation: dot1q Operational Trunking Encapsulation: dot1q Negotiation of Trunking: On Access Mode VLAN: 48 (VLAN0048) Trunking Native Mode VLAN: 48 (VLAN0048) Administrative Native VLAN tagging: enabled Voice VLAN: none Administrative private-vlan host-association: none Administrative private-vlan mapping: none Administrative private-vlan trunk native VLAN: none Administrative private-vlan trunk Native VLAN tagging: enabled Administrative private-vlan trunk encapsulation: dot1q Administrative private-vlan trunk normal VLANs: none Administrative private-vlan trunk associations: none Administrative private-vlan trunk mappings: none Operational private-vlan: none Trunking VLANs Enabled: ALL Pruning VLANs Enabled: 2-1001 Capture Mode Disabled Capture VLANs Allowed: ALL
Protected: false Unknown unicast blocked: disabled Unknown multicast blocked: disabled Appliance trust: none hq>show interface Gi1/0/3 trunk Port Mode Encapsulation Status Native vlan Gi1/0/3 on 802.1q trunking 48 Port Vlans allowed on trunk Gi1/0/3 1-4094 Port Vlans allowed and active in management domain Gi1/0/3 1-3,7,48-50 Port Vlans in spanning tree forwarding state and not pruned Gi1/0/3 1-3,7,48-50 hq> Boris. On Sun, Jan 25, 2015 at 7:05 PM, Boris Epstein <borepst...@gmail.com> wrote: > Thank you everyone. > > OK, the mystery deepens, I guess. The machine does need to support several > VLAN's, it is currently on a trunkport (8021q encapsulated), it made it > into the ARP table - which I specifically tested for by physically > unplugging the table, clearing the ARP table and plugging it back in. > > The ARP table currently looks like this: > > hq#show arp > Protocol Address Age (min) Hardware Addr Type Interface > Internet 192.168.48.100 0 0025.6440.0301 ARPA Vlan48 > Internet 192.168.48.101 - 001b.906a.bcc4 ARPA Vlan48 > Internet 192.168.48.1 0 0025.6440.063f ARPA Vlan48 > Internet 192.168.2.52 0 0025.6440.0547 ARPA Vlan2 > Internet 192.168.3.1 - 001b.906a.bcc2 ARPA Vlan3 > Internet 192.168.2.1 - 001b.906a.bcc1 ARPA Vlan2 > Internet 192.168.7.1 - 001b.906a.bcc3 ARPA Vlan7 > hq# > > The network config on the machine currently looks like this: it has > nothing assigned to eth0, eth0.48 = 192.168.48.100/24, eth0.49 = > 192.168.49.100/24, eth0.50 = 192.168.50.100/24. > > And - even though the ARP table seems to be OK - there is no connectivity! > > Boris. > > > > On Sun, Jan 25, 2015 at 11:42 AM, Les Mikesell <lesmikes...@gmail.com> > wrote: > >> On Sun, Jan 25, 2015 at 8:38 AM, Andrew Holway <andrew.hol...@gmail.com> >> wrote: >> > On 25 January 2015 at 15:12, Boris Epstein <borepst...@gmail.com> >> wrote: >> > >> >> OK... but why does it need to be a trunk port? >> >> >> > >> > Because a trunk port will "trunk" the vlan. >> > >> > A VLAN is basically a 4 byte "tag" that gets injected into the packet >> > header when the packet enters the VLAN network. When we trunk a VLAN we >> say >> > to the switch "pass packets on VLAN x but do not strip the tag out". >> > >> > You can either terminate the VLAN at the switch port (untagged) which >> will >> > strip out the VLAN tag or you can pass the packet containing the VLAN >> tag >> > to the computer or other device(tagged/trunk). This device can then pull >> > out the tag. On linux this mechanism is done by an 8021q VLAN interface. >> > >> > Hope this is useful. >> > >> >> Just to add to that - normally if a host only needs to be on one >> subnet you would use an access port on the switch to select a single >> vlan and deliver those packets untagged so the host does not need to >> care about tags or vlan numbers. And to that end, switches default >> to treating everything as access ports on native/untagged vlan 0 >> unless configured otherwise. However, if the host needs interfaces >> on multiple subnets, you can do it on a single network connection by >> giving it a trunk connection from the switch and letting it split out >> the vlan interfaces internally. >> >> -- >> Les Mikesell >> lesmikes...@gmail.com >> _______________________________________________ >> CentOS mailing list >> CentOS@centos.org >> http://lists.centos.org/mailman/listinfo/centos >> > > _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
