Need basic help extending network using two old 3550-12G switches

[dukegrad98]

Greetings.  I am an "old noob," who twenty years ago made a living working in technology...but my knowledgebase is now an unfortunate combination of rusty and outdated.  I am here requesting help of the most annoying sort -- I need some guidance on how to make my Cisco equipment do far less than it is capable of doing!  I have to think this is easy, but in spite of beating my head against it and nearly wearing out the Google and Youtube servers the past few nights, I have not made any progress and have finally given in to this plea for help. 

The scenario seems very simple:  I am trying to extend my internet connection from my home to a detached garage/workshop as well as a guest house.  A flat network is just fine.  The hardware is a hodgepodge of newer consumer-level equipment and older Cisco equipment that I have sitting around from a long-ago business.  Here is roughly what I need the "new leg" of the network to look like this:

Cablemodem/Router --1--> Media Converter --2--> Switch #1 --3--> Switch #2 --4--> (TBD:  Switch / WiFi Access Points / End Users)

Notes/specifics on the equipment involved:

• Cablemodem/Router:  Netgear C3000, a consumer-grade integrated cablemodem, router, and WiFi access point.
• Media Converter:  TP-Link MC220L, a little box with 1000Base-T copper link input from the cablemodem/router to output on a Cisco GLC-SX-MM SFP (1000Base-SX).
• Switch #1 and #2:  vintage Cisco 3550-12G models.  Yes, I have console access through putty.  For those who have forgotten, each switch has ten GBIC ports (all of mine populated with 1000Base-SX adapters) and two 1000Base-T ports.

Notes/specifics on the numbered links between the pieces of equipment:

• Link 1:  a 2' copper ethernet cable, taking gigabit ethernet from a cablemodem/router port to the media converter. 
• Link 2:  a 300m/1000' multimode fiber (50/125) from the media converter to port Gi0/1 on switch #1, using a Cisco GLC-SX-MM SFP transceiver.
• Link 3:  a 250m/800' multimode fiber (50/125) connection, from port Gi0/3 on switch #1 to port Gi0/5 on switch #2.
• Link 4:  is / will be a standard copper gigabit ethernet connection from switch #2 port Gi0/12 to whatever other dumb switch or end user device(s) I wind up using.  Odds are that it will be a fairly typical gigabit switch, with connections to a couple of 1000Base-T hard-wired machines and two or three WiFi access points. 

NOW, FINALLY, TO THE QUESTION...!  How do I configure this to work?!?  I basically just need my internet signal relayed/extended.  I don't need the switches to route, or provide DHCP, or segment V-LANs, or firewall, or any of that.  The cablemodem/router will do all of that adequately for my purposes, as long as equipment attached to the switches can see the Netgear in the first place. 

I basically just need a link between cablemodem/router and the "TBD end users" after Link 4.  I've gone eight rounds with it in a makeshift lab, to avoid the inconveniences that come once I spread out the equipment across a quarter-mile of fiber.  I once managed to ping the internet from Switch #1 console, but plugging my laptop into its Gi0/11 port still produced no internet access -- and it logically follows that I have never gotten signal to Switch #2.  I do have link lights on both switches, so I know they are physically connected, adapters are working, fiber is good, etc.  I have fiddled with more switchport mode access and spanning-tree portfast and no shut commands than I can count.  Even assigning those configurations to ALL PORTS on the switches (supposedly turning them into "dumb switches") has not resulted in any forward progress. 

I have to believe that this setup cannot be that complicated.  I'm sure someone will say I should go buy a dumb switch or two, but I figure it makes perfect sense to use the stuff already sitting around collecting dust.  (Plus, there's the fun of the challenge...or at least it was fun when I started!)  I am just too far out of the loop to sort it out, and I'd be deeply grateful for any tips or configuration command suggestions.

Thanks!
John

[Leo Laohoo]

 I am not sure if other non-Cisco switches support 802.1q trunking, but if they do, enable Trunking on the 3550.  Even though you've got a flat Layer 2 network, it's still worth doing Trunking. 

If the switches don't support trunking then put the ports into access ports (VLAN 1 default) and disable spanning-tree portfast.  

Ports facing directly to PCs then enable portfast, of course.

[Jared Burton · Accepted solution]

My two cents: The break could be in any one of those devices or even the transceivers. I don't have much experience with media converters, but I understand the desire/necessity with 12g model switches. Most 12g's after the 3550 eliminated copper ports all together.

I would try building your network out piece by piece, starting with the fewest possible pieces.

1. Router -copper- Switch1 -copper- PC. (if that works, add the second switch into the mix)

2. Router -copper- Switch1 -copper- Switch2 -copper- PC (I can't recall if the 3550 has auto mdix, you may want to find or make a crossover cable for the switch to switch connection.)

3. Router -copper- MediaConverter -fiber- Switch -fiber- Switch -Copper- PC

Keep it all on vlan 1 and let it ride. Curious to see what happens, love these make shift projects!

Cheers!

[dukegrad98]

Jared, thanks for the brilliant and logical advice on testing strategy.  After a few late nights -- probably counterproductive -- I gave it a whirl your way. 

Number 1 worked.  I had to skip Number 2 for the reason you anticipated -- the 3550 does not have auto-mdix, and I didn't have a crossover cable hanging around.  And then -- drumroll, please -- my derivative of Number 2 worked.  My long fiber runs are actually already buried in conduit.  To simulate them, I had a couple of short pigtails here in the lab.  My final test looks like this:

Router -copper- Switch1 - fiber - Switch2 -copper- PC

I'm not sure why I am not running at wirespeed on the LAN, but at this point I'll settle for consistent file transfers at ~800Mbps.  Most importantly, my laptop is also having no problem seeing the internet. 

The setup is no different than what I thought I had put together last night, which I can say with confidence did not work.  So there's "more to the story," but the immediate reaction is that things are greatly improved.  It will probably be this weekend before I have time to spread the equipment and add the media converter and long fiber runs to the mix -- but as long as the associated cables are intact, I am anticipating positive results. 

In the spirit of testing and pushing ahead while things are going well, I grabbed an old HP ProCurve 2810-48G switch from the closet and used it to simulate the end of the run beyond Link 4 in my original post.  I'm actually writing this reply from my laptop while connected there.  So right now it looks like this -- and it's working:

Router -copper- Cisco Switch1 -fiber- CiscoSwitch2 -copper- HP Switch -copper- PC

Again, sincerest thanks.  I will certainly post back when I experiment a bit more, and/or when I have it in "production" between the buildings.  I may have a couple of old Cisco wireless APs hiding out around here somewhere, so a future challenge will be trying to add them in the shop and the guest house, hopefully in standalone mode.  Stay tuned...!

Cheers, John