Question from a New networking guy.

[Scottf66]

Quick question for anyone willing to help. My boss asked me to look into a clients network. They complain of general slowness, and sluggishness. Nothing specific for apps, data, or anything else, just general slowness. First thing I recommended was that they look into upgrading to gig switches and cables. Currently they run 10/100 switches. To be honest I don't even know if their nic's support gig speeds either. These switches are not Cisco good switches. We are talking just generic switches.

Another issue is how old their network is. It was installed around 15 years ago, so i am assuming even the cabling used isn't gig compliant. He wants me to investigate this remotely, however being new, I don't know what tools are available. Yes i can google, but i wanted to ask experts what they prefer on the free side that would be good for a new networking guy to use to help diagnose their issues.

Again I know i haven't given much detail, but any tips, or anything would be appreciated. Also these tools have to be free, as my company won't re-reimburse money out of my pocket.

Thank you to all that help.

Scott

 

[sdifox]

first of all, do you have remote management rights? as in can you log into the switch and routers and pull logs.

 

[dave_the_nerd]

I would need to know what their application(s) is/are, how they use the network, and what kinds of loads they're putting on it. If all they do is surf the web and print Word docs, a 10/100 LAN is fine, but their 1.5Mbit T1 line might be a bottleneck.

You need to ascertain that first - what is the load and what are the bottlenecks. If everything lines up, then you set up a packet sniffer and start logging traffic. It's entirely possible you'll find one person streaming Netflix in the break room who's responsible for everything.

 

[Scottf66]

They use it for standard stuff. Surfing the net, erp software, file sharing, phones and printers. I did find out there phones are on the same network as the data. I have heard recently that they should be separated in a vlan. the switches they have are dumb switches. No management ability of any real kind. Cannot set port settings and so forth. They have around 70 devices plugged into the network from users/printers/phones etc.

They also seem to have a significant amount of arp messages from ipv6. Only ran the sniffer for a short time yesterday, will be running it longer today.

Any recommended tools to test throughput? I was going to use lan speed lite i believe and give it a shot.

 

[VirtualLarry]

If their switches don't support spanning-tree, it's possible that they have a network loop that's clogging up the works.

 

[Ertaz]

If their switches don't support spanning-tree, it's possible that they have a network loop that's clogging up the works.

This. Managed switches FTW.

 

[dave_the_nerd]

They use it for standard stuff. Surfing the net, erp software, file sharing, phones and printers. I did find out there phones are on the same network as the data. I have heard recently that they should be separated in a vlan. the switches they have are dumb switches. No management ability of any real kind. Cannot set port settings and so forth. They have around 70 devices plugged into the network from users/printers/phones etc.

They also seem to have a significant amount of arp messages from ipv6. Only ran the sniffer for a short time yesterday, will be running it longer today.

Any recommended tools to test throughput? I was going to use lan speed lite i believe and give it a shot.

If they're doing any heavy file transfers, and using the same VLAN for voice and data, then you don't need to do any more diagnostics. Just set 'em up with a simple managed gigabit setup, smart switches, QoS for the VoIP VLAN, etc. Standard by the book stuff. Don't bother changing their IP schema for anything but the phones (which would need a new subnet on their own VLAN.)

Downtime should be minimal - you can set up the switches (and a router) in a lab environment, swap 'em out on a Friday afternoon, and be good to go.

IPv6 is the way of the future, but you can probably disable it for an office LAN.

 

[Gryz]

They also seem to have a significant amount of arp messages from ipv6.

That's pretty cool.

Especially considering that IPv6 doesn't have any ARP.

You probably mean IPv6's Neighbor Discovery Protocol ?

 

[Zargon]

or RA's or dhcpv6 requests?

its probably windows clients being chatty


and cat5 supports gig, which has been around for 20+ years....