Tag Info

Hot answers tagged

4

You're mixing layer 2 and layer 3 together and they're two different things. VLAN's "operate" at Layer 2 while subnets "operate" at layer 3. It sounds like you have inter-vlan routing configured and you're using that to route traffic between the subnets between the two companies. When you say that you have a /30 that bridges the two switches what I suspect ...


2

If you need the same VLAN to span both switches, you need to define it on both devices and then connect them using a trunk (which also gives you the ability to carry mutiple VLANs on the same physical cable). Sample configuration (to be reapeated on both switches): interface GE0/1(or whatever port you want to use) switchport mode trunk switchport trunk ...


2

The filter port 67 or port 68 will get you the DHCP conversation itself, that is correct. The filter arp should capture arp traffic on the subnet. This is broadcast in nature, so can be caught from any port on the subnet. And the ICMP requests you've already outlined. I'd say you have the comprehensive list.


2

I settled with the following PCAP filter: ( udp and ( port 67 or port 68 ) ) or arp or ( icmp and (icmp[icmptype] == 8 or icmp[icmptype] == 0 ) ) or ( udp and ( port 546 or port 547 ) ) or ( icmp6 and ( ip6[40] == 135 or ip6[40] == 136 ) ) or dst net ff02:0:0:0:0:1:ff00::/104 or dst host ff01::1 or dst host ff02::1 or dst host ff02::1:2 or ( icmp6 and ( ...


2

I finally found the answer! After a lot of digging into various wireshark captures I noticed that when the problem was happening that there was a lot of IPV6 broadcast and discovery traffic. After additional investigation I found that various computers on our network had Intel nic cards that had a wake on lan function. The computers would sleep and would ...


2

iPXE approach is really a cowboy hack. The answer to your question is "No"; do not expect any standard PXE client (including VMware PXE ROMs) letting you set any DHCP option. Edit: NIC boot-roms will only implement the DHCP options required by the PXE standard. What you are trying to do is not standard then you will not find any vendor willing to provide ...


2

Sure. Don't bind DHCP to the first NIC. Don't create a DHCP Scope for the first NIC's subnet. Either of these will do the job, it's not necessary to do both.


2

You can't use 192.168.0.0 as the IP address on the router / DHCP server. With a /24 subnet (netmask 255.255.255.0) the first usable IP address is 192.168.0.1. For more information as to why see this previous Q&A.


1

Yes, create a reservation for the mac on your DHCP server.


1

First off, I'd be rather curious to know why you'd want geographically diverse DHCP servers. Local redundancy, sure -- maintenance, server crash, etc -- but if a site is so hosed that both of a HA pair (or cluster) of DHCP servers was down, I'm betting that you'll have bigger problems to worry about than whether desktop PCs are getting their DHCP requests. ...


1

VMware Fusion provides its own DHCP-server in the Host-Only network ('private to my mac'). This DHCP-server collides with the Windows Server 2012 DHCP service. You may whether create a new private network with DHCP and NAT disabled in VMware Fusion -> Preferences -> Network and move both VMs' interfaces to it or disable DHCP in the preconfigured Host-Only ...



Only top voted, non community-wiki answers of a minimum length are eligible