Router? Switch? What do I need?

[kopar]

I had this posted in the Win 2K forum, but I think the topic has drifted into this forum's scope.

I am re-engineering the network topology in my organization and I have decided on creating multiple segments (subnets) with a single DC, DHCP, DNS server serving all the subnets.

I understand that I will need some hardware in place that will separate the network into logical units, but I'm not exactly clear on the exact hardware I will need.

Is it a managed switch? Or a router? Also, I would like to know if there are any standout managed switches/routers that will allow me to do the following:

1) Create multiple network segments (10.2.x.x, 10.3,x,x, etc.)
2) Do DHCP unicast forwarding (from each subnet to the primary DNS/DHCP server)
3) Allow each segment to communicate (10.2.x.x can talk to 10.3.x.x efficiently) as if on a single network.

Also opinions about CLI interface and web admin interface preferences are certainly welcome.

Thanks in Advance!

-Tom

 

[mtashiro]

Answer....

Both a router and a switch. The switch will create the VLAN's (sepearate logical units or subnets) and the router will allow connectivity (routing of the subnets) between the subnets.

Cisco makes several switches that has routing built in from a simple 24 port version (3550) to the high end 6500 with a MFSC (router). You didn't say how many ports you needed so it will be difficult to give you specifics.

Most vendors have switches with routing capability as well.

 

[MJewell]

to Give you an idea of sizes, I have 12 4006's (+1 spare) with about 240 ports in each all uplink to a 6509 as my main switch with Dual Sups/MSFC's

If you want to go with the Higher end 6509 as a core switch, I would not recomend you purchase the 48 port copper blades for it, there extremely expensive... for the cost of 1 blade, you can purchase a 4006 with the redundent power supply and a 48 port copper blade...

I have 6 Vlans with:
1 for switches management interface (255.255.255.224 32add)
4 255.255.254.0 (510 addresses ea)
1 255.255.255.0 (254 addresses)
1 for WAN connection to my provider (255.255.255.248 6add)

You may not need that many vlans, all depends on your layout...



-Mike

 

[kopar]

Thanks for the info.
I think that we would only need a small setup, as the size of our business isn't tremendous, but will be growing. Currently we have a series of unmanaged switches handling the network traffic and it's working well for us. I beleive that a 24 port multilayer switch would perform for us quite well, if it meets the following qualifications:

a) Allows unmanaged switches to be added as end users increase.
b) is stackable to increase port numbers as unmanaged switches increase.
c) follows all guidelines expressed in my original post

The 3550 is a bit pricier than I was thinking, but I wasn't thinking along the lines of needing both a router and a switch.

Thanks again!

 

[MJewell]

Well, if your interested in breaking your network up into segments and want to have 1 integrated box, the the 3550 would probbaly be your best choice, although if you don't mind having 2 seperate pieces of equipment, then maybe a 2950 series switch and a 2600 series router would be a better option. I know that 2500 & 2600 series routers can be found fairly cheep used, even see a few on Ebay...

Don't be afraid to ask for help if your not all that familiar with them or configuring them, it's better to ask for help then to leave your network wide open...



-Mike

 

[BuckWeet]

Don't use a 2600 as a MLS device, the performance isn't there..

Either look at the 3550 or 3700 series switches.


BuckWeet

 

[MJewell]

I don't really have much experience with using stand alone routers for MLS, so I would have to defer this to others here...

-Mike

 

[kopar]

Okay. I think we have made a decision on what we are going to do, ut we just don't know what we need.

We will have 4-5 network segments.
We will not be using VLANS to separate them
Each segment will have it's own DNS/DHCP server (legacy solution)

I beleive that a Cisco 2600 series router is what we will need to accomplish this. Will we need anyhing else? Managed switches, etc.? Or will the 2600, coupled with the DNS/DHCP servers on each network be sufficient?

---Rough Map---

((Internet))
|
|
[[Firewall PIX]]
|
|
<<Cisco 2600>>-----{10.2.x.x}dns/dhcp(Win2K/AD)
| |
| |
{10.3} {10.4}
dhcp/dns dhcp/dns
lnx lnx

I can't really express this any clearer than this diagram.

PS: You guys have been more than informative, and you all are lifesavers!!!

 

[baddos]

Don't expect the 2600 to have a high throughput between each segment. I would recommend removing the 2600, and replacing it with a Cisco 3550 switch. It you remove the switchport, and just make them regular interfaces if you like to try to duplicate the 2600 config.

Also, you don't need dns and dhcp servers on each segment. You should have a dns server in your main segment, and maybe another in a separate segment. Place your DHCP server in your maing segment and setup multiple DHCP scopes. Then setup your router (l3 switch or router) with the ip helper xxx.xxx.xxx.xxx command on each interface (expect the one with the DHCP server).

I.E.

((Internet))
|
|
[[Firewall PIX]]
|
|
<<Cisco 3550>>-----{10.2.x.x}dns/dhcp(Win2K/AD)
| |
| |
{10.3} {10.4}
dns / lnx lnx

Interface for segment 10.3 and 10.4 have this in their config: ip helper 10.2.x.x(the IP of DHCP server)

 

[NetEng631]

I Agree with Baddos.

You are very limited to the number of Interfaces and throughput on a 2600. Each Interface on a 3550 can be assigned to any VLAN and each vlan can become it's own L3 segment(an interface on a router). Instead of stacking all your switches you can also connected them directly into the 3550. So if you can afford it. it's a better solution.

Also having multiple DHCP and DNS servers are a pain to manage. Save yourself some work. It will be a lot of work in the beginning to transition, but once it's finished it will be much easier.

The IP Helper address is much easier. That what the code was developed for.

 

[kopar]

Just ordered the 3550.

Thanks a TON for all your help everybody. I now have much firmer grasp on networking technologues and possibilities for our company in the future.

--Tom

 

[jpm121]

I think you'll be happy with the 3550, based on how you described things. Keep in mind that in the router method described above, the routing will be throttled at 100Mbps (i.e. the ethernet port on the 26xx router). The 3550 will be doing the same thing on its 6 (??) Gbps backplane. Much better performance, as you can imagine.

The 3550 can also grow very easily via fiber uplinks with GBICs. Smart move.