At the moment I have a need for a small 4 or 5-port managed switch. Just basically be able to login remotely, see if link on a given port is up for diagnostics, maybe a few config changes on rare occasion.

First thought popped into my head was:

1) Load OpenWRT
2) Disable WiFi
3) Move WAN port to LAN side

I can't see any downsides to this.  Considering the GL is $55 right now, if there's a cheaper path to a managed switch I haven't found it. Am I missing something?

That should work.  I always thought of managed switches and routers as those capable of being controlled via SNMP and RMON (or RMON2).  In a small network you probably wouldn't need all that stuff since, as you say, if changes are rare you can just log in to it and make them.

I notice there is nothing for RMON on Linux and the RFCs for it have been stable for 10 years now.  I can't decide if this represents an opportunity or is indicative of a world where nobody actually uses RMON.  Commercial products that use RMON probes are insanely expensive.  SNMP itself is something of a black art I guess.

I only bring this up because I did some research a few weeks ago about managed network devices along these lines and it sort of applies to your question.

Good luck with trunking or creating span ports. For a simple managed switch, which won't run at full speed (ie: snmp, portup/portdown) you should be good to go. Are you looking to hit it with mrtg or anything like that?

I hadn't thought ahead to SNMP etc. although those might be nice. Good ideas!

However, at the moment I'm trying to remotely debug problems in a small network. The setup there is things starred around a dumb 5-port switch right now. It's a lights-out setup at a remote site, so digging someone up to go hold a phone and look at things is the next step but I like to have as much advance information as possible before doing that.

So at least having a switch I could LOGIN TO would be a big step up. I can get into the gateway device and it shows link on the right port but cannot get beyond that. So no way to tell if the switch is hung or what's going on. I just know on the gateway I see link so assumedly the dumb switch is powered on.

With some sort of managed switch, I could get further into the problem. I could tell if a node were "UP" in the sense of being powered and showing link, but perhaps locked up.  It's possible the gateway and switch have power and something has knocked out the circuit that the other nodes are  on, and it would be apparent from looking at the link indicators if they were all down.

I am not conversant in REAL switch work, so can't say if this would officially be designated a managed switch. So perhaps my subject line is incorrect.

(Last edited by vincentfox on 14 Mar 2006, 23:26)

Trunking is no problem, I've got a dozen units doing trunking. Span ports and "full speed" are somewhat irrelevant in a wireless environment where typical traffic is < 3mbps but certainly could be a factor in a wired network. But for a wired network why not just use a real managed switch. The last HP Procurve 2400m 24 port managed 10/100 switch cost me $40 on ebay.

- DL

Going across the switch shouldn't really impact speed, but going from the switch through the router's network interfaces, kernel routing tables and firewall rules then back out the switch .. well yeah there's a performance hit there.

You are  a better shopper than I am.

I just did a search on EBay and found a single 2400m for auction, buy it now price $170.

Ebay shopping is an art. The one I bought is actually a 1600m but has the module so it's equivalent to the 2400m.
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi … 5860911376

- DL

I've got a couple "legacy" HP managed switches in my junkpile. They're only 10mb but in my junkpile because they don't support vlans - won't even pass mtu sized vlan tagged packets. If anyone wants to pay shipping +$10 for my trouble? fwiw both were in peripheral areas of our network where 10mb was more than enough, but I'm vlan tagged everywhere now so I replaced them with wrt54's.

Checking ebay I also noticed that 80 port 4000m's are now in the ~$350 range so I may buy one to replace a stack of 3 24 port procurves I have at one location. If I do I may have a couple 24 port ones for sale cheap.

- DL

OpenWRT as a switch is interesting for me cause there is no other combination of the following simple features:

- simple remote diagnostics
- VLAN 802.1q support with tagged ports
- fanless (!)

The only alternative is a Cisco 2940-T which costs $400+ - ok is has a 1000 more features -
but i do not know any other combination with these three simple features combined.

Axel

I found that DD-WRT allow the user to utilize vlan, tag and trunk, is there anybody complete implement these function within production environment?
how the use two UTPs to connect two WRT54G and implement trunk?