New answers tagged

1

You can do this, but the exact terminology will vary depending on which switch vendor you are using. On Cisco equipment it's the 'Native VLAN' most vendors will have something similar (and probably close to that name since most try to emulate the Cisco interface).


1

You didn't provide an OS for the server machine, so I'm going to make several assumptions here. You can use iptables for this on Linux servers (i.e. configure the server to act as a router). First, you need to enable IP routing on the server machine: sysctl -w net.ipv4.conf.all.forwarding=1 Let's assume the vlans are both connected to the server on eth1 ...


3

In short, no this is not possible. To cross VLANs, you need a layer 3 device (L3 switch or a router). I'm going to assume that you have no control over the ISP CPE and say that you will need to acquire some additional equipment before making this setup work.


0

See https://wiki.wireshark.org/Ethernet and https://wiki.wireshark.org/VLAN If the type/length field is: 0 - 1500: length field (IEEE 802.3 and/or 802.2) 0x0800: IP(v4), Internet Protocol version 4 0x0806: ARP, Address Resolution Protocol 0x8100: IEEE 802.1Q frame 0x86dd: IPv6, Internet Protocol version 6 So if the type/length field is 0x8100 then the ...


0

How do I accurately predict the size of IPv4 packets with vLAN tags from reading the header? IPv4 packets do not have VLAN tags in the header. Only the ethernet frame (layer-2) header will have VLAN tags. An IPv4 packet (layer-3) is the payload of the frame, and the IPv4 packet header will not know anything about what is in the frame header. These are ...


0

You can't have two untagged VLANs on a single switch port, and wouldn't want to do that regardless. You'll likely need two NICs in your machine, one on each VLAN, if you can't route between the VLANs. If your OS supports VLAN tagging and treating that as a separate interface, you could have one untagged and one tagged VLAN configured to do that on a single ...


0

Can private ip address mixed with public ip address without nat? Yes they can. As long as routes are available for the packets to flow in both directions the endpoints won't need to know or care that one address is public and the other is private. If things won't work without NAT enabled my guess would be that your return route is broken.


1

You're using /24 on one switch and /28 on the other. That means 192.168.0.1 thinks 192.168.0.17 is in the same subnet, it is not. You'll need to route between the networks.



Top 50 recent answers are included