Cascaded Routers?

[dthunderbird]

Or what ever it is actually called, if it would even work?

I have a trendnet 4 port router and musta said I could use 5 ports so my bro got me a wrt54g and I guess it is 5 ports sorta just one is wireless.

To the point can one be plugged into the other thereby giving me 7 ports and a wireless connection?

Thanks

T

 

[jdabbs]

You don't want a true cascade, as that causes additional work in NAT troubleshooting. Both routers can be connected together though.

I'd have the WRT54G connected to the Internet with a cable going from a LAN port on the 54G to a LAN port on the TRENDnet router. Make sure you disable DHCP on the TRENDnet router. It's important to use the LAN ports instead of the WAN, as this may cause the aforementioned NAT issues as well as segmenting the network (which may affect LAN gaming).

If both routers are 4 LAN + 1 WAN, that should leave you with six LAN ports available.

 

[YeOldeStonecat]

I don't like double NAT'ing..which is what happens if you place 1x router behind another router. Can lead to performance issues, some internet based applications don't like it, and if both routers are in the same IP range by default (which many are..192.168.1.xxx)...that inside router will get all sorts of confused...."Which way do I go George?"

Say you primary router is 192.168.1.1
Take your second router...make its LAN IP address in the same range..but outside the DHCP pool. A standard access point IP is something like 192.168.1.245 or 192.168.1.253...so make it one of those.

Disable DHCP services on the 2nd router (you don't want more than 1x DHCP service on the same network in 99% of cases).

Now uplink them using a LAN port on each of them..you will not use the WAN/Internet port of your second router.

Now it's been McGuyvered to run basically just as an access point, traffic will stay on the LAN side of it since it's not being used as a gateway.

 

[scotty]

I don't like double NAT'ing..which is what happens if you place 1x router behind another router. Can lead to performance issues, some internet based applications don't like it, and if both routers are in the same IP range by default (which many are..192.168.1.xxx)...that inside router will get all sorts of confused...."Which way do I go George?"

Say you primary router is 192.168.1.1
Take your second router...make its LAN IP address in the same range..but outside the DHCP pool. A standard access point IP is something like 192.168.1.245 or 192.168.1.253...so make it one of those.

Disable DHCP services on the 2nd router (you don't want more than 1x DHCP service on the same network in 99% of cases).

Now uplink them using a LAN port on each of them..you will not use the WAN/Internet port of your second router.

Now it's been McGuyvered to run basically just as an access point, traffic will stay on the LAN side of it since it's not being used as a gateway.

That'll do it. Great advice.

You can turn virtually any router into a simple 'switch' simply by disabling DHCP, and making sure it doesn't have the same address as another router (i.e. multiple 192.168.1.1 devices). With that, a router basically turns into a switch / Access-Point, and you can 'cascade' / daisy-chain as many as you want.

No real need most of the time to leave them as-is and do double-nat'ing as stonecat mentions, unless your desire is multiple private LANs or something of the sort.

 

[YeOldeStonecat]

turns into a switch / Access-Point, and you can 'cascade' / daisy-chain as many as you want.

Yup...I've done a few of those, router at 192.168.1.1, and several wireless router flipped to an AP, 192.168.1.245, 192.168.1.244, 192.168.1.243, etc etc.

 

[corndog]

Just for fun once, I got together with a few friends and we all brought some routers we had lying around. We managed to get cascaded NAT routers hooked up 10 deep and it still worked. The performance wasn't all that bad either.

In a half decent router, NAT should work with barely any impact in performance - except for NATing things that weren't designed to NAT, like IPSec (requires packet mangling). There are usually 10 to 20 hops between your internet connection and the destination server you're accessing anyway - all you've done is just add a few more hops. And these hops are likely not the slowest link anyway. 10meg cascaded routers won't slow your connection below a 2meg internet connection.

 

[YeOldeStonecat]

Just for fun once, I got together with a few friends and we all brought some routers we had lying around. We managed to get cascaded NAT routers hooked up 10 deep and it still worked. The performance wasn't all that bad either.

What did you test it with?

While pure web browsing often works, and some online games..other things like...

some remote desktop programs...I recall PcAnywhere....goes to a black screen at times (not that I use PcAnywhere anymore with RDC taking over).

VoIP can suffer a bit

file transfers within IM applications

Some ASP hosted programs

 

[corndog]

We tested http, ssl, pop, openvpn, IPSec, MSN, ICQ

IPSec fared the worst. Most of the others had no noticeable slowdown.

 

[thiggins]

I have always run double-NATed since my DSL "modem" is actually a router.

I've never had a problem. But needs are simple, i.e. no servers, no VPN, etc.
Skype, GoToMeeting, WebEx, etc. work fine. No problem with VoIP either, when I used it.

 

[corndog]

I do something similar. For most of my own traffic I single NAT through my Linux firewall/router. But all inbound traffic gets DNATed through to my Dlink GamerLounge router. The PSP, Xbox360, and Wii all connect to the D-Link, which does uPnP. Makes online gaming work nicely.

My kids triple-NAT through a Juniper, to a yoggie, and then finally to the Linux firewall/router.

 

[dthunderbird]

I don't like double NAT'ing..

Now it's been McGuyvered to run basically just as an access point, traffic will stay on the LAN side of it since it's not being used as a gateway.

I think I understand now, why when I plugged and prayed it didn't answer. I'll try the LAN to LAN. Question tho if the traffic stays on the LAN side does that mean the second router connections won't see the cable modem/internet? ( I'll know the answer this weakend but it might be nice for others reading this thread.)

Thanks y'all,
T

 

[aos]

One way to avoid double NAT when you are forced to use two routers - e.g. because your ISP provides you with modem/router combo - is to set up the first router to place the second one in a DMZ. That way you are hopefully bypassing the first one completely, avoiding any issues over which you likely have no control and worse no recourse over. E.g. my old D-Link regular router could freeze if faced with a large FTP/HTTP transfer and say normal wireless traffic at the same time. If you were to run into that issue with ISP-provided router/modem, you'd be SOL as you likely can't replace it with a different model.
By disabling firewalling and routing on that modem you're hopefully reducing its workload, reducing or eliminating chance of reboots or freezes.

This won't help if you must absolutely use ports on the first router for whatever reason (likely money or burning desire to not have yet another box (switch) to clutter the room).

 

[thiggins]

DMZ can help, depending on how it is implemented. Remember that when you are using DMZ on consumer routers, you are still going through the routing engine. It's just supposedly passing traffic on all ports and protocols.

As I have found in my testing, however, "DMZ" doesn't ensure that packets pass unchanged. In many cases a router's SPI (Stateful Packet Inspection) routines are still applied to the packets, which can effect some applications (IxChariot for example).

 

[YeOldeStonecat]

One way to avoid double NAT when you are forced to use two routers - e.g. because your ISP provides you with modem/router combo - is to set up the first router to place the second one in a DMZ. y or burning desire to not have yet another box (switch) to clutter the room).

I configure the ISP supplied box into "bridged" mode.