Jumbo Frames?

[ddrueding]

Unless the jumbo-frame devices were connected to both virtual networks, then they would communicate with those that could handle it with them, and those that couldn't without them; provided their NIC could intelligently switch the feature on and off depending on what VLAN they were on.*

Of course, this is the issue anyway; NICs should be able to auto-negotiate this kind of thing, and they obviously can't, or we wouldn't be talking about it for so long!

 

[Stereodude]

Unless the jumbo-frame devices were connected to both virtual networks, then they would communicate with those that could handle it with them, and those that couldn't without them; provided their NIC could intelligently switch the feature on and off depending on what VLAN they were on.*

Of course, this is the issue anyway; NICs should be able to auto-negotiate this kind of thing, and they obviously can't, or we wouldn't be talking about it for so long!

You can put the gigabit NICs on both VLANs though with just a single cable. Most gigabit NICs support 802.1q which allows you to put them on both VLANs. I don't know if they would be smart enough to file share amongst themselves on the faster VLAN or not though, or if you could force it though.

 

[Stereodude]

No that is not what a vlan does, it will prevent communication to and from the different vlan's so that the non gigabit and the gigabit networks can not communicate to each other. You will still need to connect the two virtual networks via a router.

A vlan creates separate virtual lans on the same physical network. It is as if they were on separate physical networks, but they are not. As such, you still need a router to communicate between them.

That wasn't my point though. You can put the gigibit adapters on both VLANs through their support of 802.1q. Then, you wouldn't need a router because you're technically not connecting the two VLANs. The faster machines would be on both VLANs with only a single NIC. They would get internet access and file serve to the slower non Jumbo frame supporting VLAN. They would file share between themselves on the faster Jumbo frame supporting VLAN.

 

[P5-133XL]

That wasn't my point though. You can put the gigibit adapters on both VLANs through their support of 802.1q. Then, you wouldn't need a router because you're technically not connecting the two VLANs. The faster machines would be on both VLANs with only a single NIC. They would get internet access and file serve to the slower non Jumbo frame supporting VLAN. They would file share between themselves on the faster Jumbo frame supporting VLAN.

With Windows, each NIC can actually have multiple IP addresses but you only get one jumbo-frame setting per NIC so a single NIC won't work: You still need two NIC's on each machine (one for each network). At that point, you could theoretically get rid of "the" router: each machine is acting as a router!

The Vlan switch only means you don't have to have multiple switches for this to work ...

 

[Stereodude]

With Windows, each NIC can actually have multiple IP addresses but you only get one jumbo-frame setting per NIC so a single NIC won't work: You still need two NIC's on each machine (one for each network). At that point, you could theoretically get rid of "the" router: each machine is acting as a router!

The Vlan switch only means you don't have to have multiple switches for this to work ...

Look, I'm not trying to be a dick, but that's just not true. 802.1q VLANs are not the same as assigning multiple IPs to a NIC in windows. When you set up the VLANs using the NIC's VLAN utility you can control jumbo frames setting per VLAN.

Here is a screen shot from the Marvel utility for the gigabit NIC in my work laptop.

 

[ddrueding]

Here is a screen shot from the Marvel utility for the gigabit NIC in my work laptop.

Sweet. I hadn't seen that before...

 

[P5-133XL]

I've never before seen that capability in a NIC: I agree that is sweet and appears to do exactly what needs to be done to get rid of routers and multiple NIC's. For the rest of us, we are stuck doing it the painful way.

 

[Stereodude]

I've never before seen that capability in a NIC: I agree that is sweet and appears to do exactly what needs to be done to get rid of routers and multiple NIC's. For the rest of us, we are stuck doing it the painful way.

Apparently the Intel gigabit cards support it too.

Scroll towards the bottom of this page to see it.

 

[ddrueding]

So...next we need to find the cheapest switch that supports this functionality.

Ton's of cheap NIC's support 802.1q.

...and some cheap Switches.

...and some NAS devices.

But I didn't see any cheap-ish routers with GbE and 802.1q.

 

[sechs]

My nForce ethernet has some VLAN options. I dare not touch them, in case the motherboard explodes, but they're there.

Looking at the fact that you'll have to shell out for managed switch, wouldn't be cheaper and easier to go with the separate physical networks and a bridging router?

 

[Stereodude]

But I didn't see any cheap-ish routers with GbE and 802.1q.

They don't need to.

I think what you do is connect all the 10/100 Base-T devices (which are, presumably, older) to your switch. They would be members of the default VLAN (usually VLAN 0), which is untagged. You can have only 1 untagged (native) VLAN. Or you could use a port based VLAN for them (set by your "smart" switch) You then connect your (smarter, modern) 1000 Base-T devices to the same switch, but set them up to tag their jumbo frame traffic as VLAN 1. You then add a second VLAN on the 1000 Base-T devices with jumbo frames turned off on the default VLAN.

What happens next / if the cards will figure out which VLAN is faster for transfers, or how it decides which VLAN to use is what I don't know.

And FWIW, I've been told it should be written 802.1Q, not 802.1q. Apparently the uppercase letter means the standard has been ratified.

 

[Stereodude]

Looking at the fact that you'll have to shell out for managed switch, wouldn't be cheaper and easier to go with the separate physical networks and a bridging router?

Cheaper, maybe... Easier, probably not. After reading P5-133XL's post I wouldn't want to attempt it.

 

[sechs]

I find it easier to troubleshoot "is the cable plugged into the right thing" than "did they write their driver correctly."

 

[Stereodude]

Ok, so another really tech savvy friend of mine says this can be done without a router and all the associated headache. He said you can "connect" the two VLANs or physical LANs together with a bridge device. He recommended a particular VM image (a modified version of Sieve) running on VMware server with two NICs bound to it. One on each VLAN. He said the NICs don't have IPs and they simply repeat all traffic from the one NIC port to the other (similar to what a hub does).

 

[Bozo]

XP supports bridging.

Bozo :joker:

 

[Stereodude]

XP supports bridging.

Bozo :joker:

Yes, you're right it does...

http://www.microsoft.com/resources/.../en-us/hnw_understanding_bridge.mspx?mfr=true