catch21

Got it up and running with another Cisco box.

What problem are you trying to solve? What size cabinet do you need and what are you going to put in there? I'm not seeing why, in our climate, you would need an air-conditioned environment. What temperature are you aiming to run the cabinet at? Why not heat it in the winter and run it at a constant 30 degrees? You need to do three things to prolong the life of your equipment: 1) Provide an environment with as constant a temperature as possible within the operating temperature range of the equipment. 2) Provide some panic measures if the temperature should reach or exceed the maximum operating temperature. 3) Avoid air-recirculation in which the air is heated and re-heated. How? 1) Use cabinet doors and blanking plates to create thermal mass. Do not open the doors unless you have to. Remember when your mum baked a cake and you couldn't open the oven door to look? Spread your powered equipment across sufficient cabinet space. 2) Install a top-of-rack fan unit with thermostatic control to switch in at 40 degrees. Install some room or cupboard air-extraction ideally to switch in when the temperature inside the cupboard/room (at ceiling level) is more than 10 degrees higher than outside (differential thermostat) 3) Use blanking plates in the cabinet to create a chimney and carry the heated air up and away, to prevent it re-circulating and being re-heated.

As soon as they have your work number they'll become incapable of helping themselves. I think its the price you've had to pay for not investing in your own phone. If it were me, iphone or no iphone, I'd hand it back.

What budget do you have for the AP? It would be helpful to sketch a network diagram as you see it, and put make and model of boxes on the sketch as you can. TBH you probably don't even need to configure a static IP. Your 2003 server should give out an IP address for the box an off you go. Your network sounds like ours was about 6 years ago. Pretty much all that's the same with us today is the cabling.

I thought I had my head around an interface VLAN, being an IP you could address packets to for forwarding across VLANs but there is no mention in the 300 series manuals. Is it possibly the same as the Administrative IP that you point a browser at the to the web-management GUI up, just that one IP used for two purposes?

I have just understood that internet connection sharing behind our (given to us) private IP address scheme is permissible on our system. Essentially, what I am thinking now is to commission a second router behind the service provider's router to 1) Pass the given private IP address LAN straight through (this LAN has a Windows 2008 server) 2) Provide DHCP functions etc to the new private LANs I would like to implement across site (using the VLAN capability of the new switches) and NAT for internet access. Can anyone recommend a box to do these functions please? I've just put in four Cisco switches so would prefer to stick with this manufacturer.

from what I recall...something like configure interface vlan 1 ip address xxx.xxx.xxx.xx mmm.mmm.mmm.mm and exit, exit, exit ...then back onto the browser UI to save there.

I managed to CLI via the console interface and hyper terminal on a windows PC. Once you can talk to it again you can set up via the web browser a management interface for each vlan (up to 32 different IP addresses I think).

Its management IP address has been changed? Can you get a console lead onto it and show the IP address that way?

I'm still getting my head around concepts. I've a network of five Cisco 300 switches with a single VLAN deployment. If I move to multiple VLANs is it basically true that I only need one of the switches in layer 3 mode with a static route set to interconnect the VLANs? I visualise it like a 'router-on-a-stick' configuration where its a switch-on-a-stick rather than a router. Am I on the right lines?

I'll stop posting these soon. Fortunately I have a 10-port version off to the side on the bench that I am putting trial configurations into before I put them onto the live switches. From factory settings, the box gets its administration (web browser) IP address from the DHCP server. That's fine, but even if I fix that to static when I switch to layer 3 mode it reverts to dynamic and picks an IP address up out of the pool again. Trouble is, I cannot then move to a static IP address (as far as I can see) and overwrite the one it is using from the pool. Once the sw is in layer 3 mode the "Change Device IP Address" on the Getting Started page takes you to "IPv4 Interface". If you try to tick and edit vlan1 you can check the Static IP box but doesn't allow the IP address to be changed? Can anyone shed any light please? Clearly I don't want a static IP set to one of the IPs out of the pool. ...and, once you are in static IP mode you can't go back to dynamic, it is greyed out. Can scarcely believe these are browser bugs but what is the alternate logic?

I'm having a bit of difficulty teasing out of the documentation what you actually lose going to layer 3 mode rather than layer 2. Is there a simple answer?

Thanks, you must have some equipment in there to produce enough heat to fry with.

Wonderful, thanks.

Does anyone know of a way to look at a distribution of link utilisation percentages on the Cisco 300 series range of switches? Packet counters are all very well but you can't see if a link is running hot. Thanks!

Thanks for the replies. The cabinet (arrived today and partly in) has gone in a cupboard so access is really limited. I did start with it mounted on the rear rails as it happens, but down at the bottom at the front will be much more convenient and doesn't look untidy with the plugs neatly labelled.

Now its sorted can I ask what happened in your switch room? What sort of temperature control did you have in place and what failed? What can we learn from your misfortune?

If you had a new 27U cabinet with three new switches to install , would you: 1) mount the power distribution block (6-way also rack mounted if necessary) at the bottom of the cabinet so the plugs and sockets are available or 2) leave the distribution block sitting in the bottom of the cabinet and cover the gap it would have gone in with a 2U blanking plate? Solution 1 is more practical, less tidy and prone to Billy-Halfwit unplugging stuff. Solution 2 is neat and tidy, safe from finger-poken but slightly less convenient for occasional maintenance. Looking forward to hearing your thoughts.

Yes, they were new and thanks for the thoughts. I used my RPi in the end to do exactly as you say because its, and you're not supposed to use the "T" word in schools, slightly less thick than a PC which is more likely to give up without trying for an address than succeeding. My rant was more directed towards the (IMHO) deeply esoteric CLI or more specifically towards the quick start guide designer who didn't think or couldn't be bothered to include the five or so lines of commands needed to set a static IP address, save and exit.

Ah, the joys of CLI and quick-start guides written by people who know how to do things. e.g. "use the CLI to set your IP address" I used maximop and george 3 in the mid 70's which were less opaque than CLI and must be the longest persisting joke in history. Anyway the challenge is to get a web browser session going on it. (Them, everything is x 5) I can't see the default IP address as its not my network id and putting the switch on the network gives it a dynamic IP address from a large pool. What am I supposed to do, guess? OK so I can get onto the 2008 server and see what's happening but what if you can't? As the quick start guide says, use the console interface, but then doesn't proceed to tell you how. What I ended up doing was nmapping the n/w once it had received a dynamic IP address and looked for the base MAC address. For one of the switches that didn't work for some reason and I had to use my RPi to talk to it initially on its default address. Anyway we're getting there, thank goodness for a small amount of networking knowledge and equipment and the web-based configuration. Personally I think that CLI is something left well behind.

I flippin' hope they're all right I've had five arrive on site today

The next host name I'm going to use is definately "Docker".

You can either be popular or impose IT policy but its hard to be both at the same time!

There's a forward DNS lookup and a reverse DNS lookup. Are both set up on the server?

I'm replacing the aging ethernet switches at our school. My plan is to use a 28 port as the core, a 28 port to aggregate non-wifi traffic and 2 x 10 port PoE to host and aggregate traffic from the wireless access points. Does anybody have any show-stopping reasons why not? They seem competitively priced to me.