sillysi

I have always used fixed IP addressing, I have 10 servers and around 100 PCs with various hubs/switches/print servers. We are putting a new SQL application in and have been advised to change to DHCP over fixed addresses mainly for increasing network speed and reducing bottlenecks when printing. Now my question is are they right in this advice and which of my servers should become the DHCP server?

Si.

ADP

In my understanding DHCP makes admin of your network much simpler, you define a range op IP adressess and then all your devices get assigned one in that range. Also helps avoid IP clashes etc

I only run a small network, so in our case the DC is the DHCP server.

Andy

beemerboy

NT4 or 2K ??

dhcp just saves faffing around with manual configs.
for that number of users, i would use DHCP to begin with,
but as long as you know what your doing, and if manual addressing has already been setup, why change??

i'd get the SQL bods to justify their case and see if its worthwhile changing.

i'd be interested to know if anyone has experienced any greater network connectivity from this change....

bb

carl

All I can see DHCP offering you is ease of implementation and maintenance, and scalability. As long as you're managing your static addresses properly (e.g. allocating the subnets properly and not wasting address space) I don't see how there would be any performance impact.

sillysi

The DC and PDC are both NT4, I have a mix of NT4 and W2K. 10 years ago when the network was small I made a decision to use fixed addressing and personaly don't see any reason to change. I may just change the PCs that are going to use the SQL app' to use DHCP and leave the rest alone. My boss is the type who believes everything IT consultants tell him.

[Edited by sillysi - 10/16/2002 12:20:22 PM]

beemerboy

i have also had probs with ip address bound to cards not releasing properly and therfore had to manually iprelease/iprenew from command line.

which can leave users fooked up for a bit, particularly if your stuck on a train.

also, i know all the servers and desktop ip's in my head, which makes troubleshooting easier.(a spreadsheet will do!!)

BB

GaryK

Si,

increasing SQL performance using DHCP? thats a new one on me, I thought that the only difference being dynamic IPs as opposed to static ones the transport will be the same and make no difference. Ive done apps that use client side SQL connecting via ADO across IP as well as server side stuff returning packets on both DHCP and fixed and cant notice any difference.

Its gonna depend more on how the app is structured, size of result sets, client/server side cursors etc.

Gary

[Edited by GaryK - 10/16/2002 12:10:28 PM]

beemerboy

sorry forgot this bit.

only one rule in IT...."If it works...leave it alone!!!!"
(took me 8 years to believe it mind you!!!!)
bb

LanCat

dhcp won't improve network performance/printing or indeed the performance of anything I can think of. What it does do is simplify any future changes you might need to make by saving you visiting 100 systems to change any network settings.

Best way to go is to use static ip addresses for the servers and dhcp for the clients. Reserve a batch of addresses for servers and other network h/w and set dhcp up on the rest.

Printing bottlenecks are a different kettle of fish and you'd need to tell us more about what you have there...

ozzy

Static vs DHCP makes *NO DIFFERENCE WHATSOEVER* to network performance or printing bottlenecks

In fact you could argue that moving to DHCP will cause slightly more traffic as the workstations will need to *find* a DHCP server everytime they boot. That will generate slighly more packets. Once it has an IP address, then it's business as usual - no difference from been given a static one in the first place.

DHCP helps with the admin of the network - period. I use it here on around 150 workstations. It saves time adding new PC's coz I don't need to note down any IP address of a new or rebuilt workstation. I just use DHCP admin if I need to track down a PC's IP Address.

If you use WINS, then all you need to know is a workstation name and it'll give you the IP address from that.

You can use DHCP to push out other info as well as a plain IP address; like WINS servers, DNS servers, Default Routers, etc.. So, if you need to change a particular IP setting, then you could easily roll-out the mod using DHCP rather than having to make the change manually on every PC. If you've got 20+, I'd use DHCP anyway.

Stefan

carl

I was going to say that, but I thought it was pedantic

Puff The Magic Wagon!

iTrader: (2)

That IP thing in SQL is down to a confusion with the transport type between the server/client?

"named pipes", "multiprotocol" etc

Changing those sometimes has a dramatic effect on the ability of the response of an SQL server.

Just a thought that maybe what they're talking about but getting it mixed up.

ozzy

Si,

The servers and print servers should use static IP addresses i.e. things that everyone need to access should be static. Only the workstations should be configured with DHCP.

We have 8 printers directly attached to the network here and print to them via NT, Unix and Novell. I've never heard of any printing problems purely related to whether a PC has a static or dynamic IP address.

You (from any workstation) send a print job to the server (whether it's NT, Unix or whatever). Once the job is spooled from the client, it's down to the server and printer communication as to how the job is printed. If these are both static, then I can't see how it could be a problem.

Once a workstation has been given an IP address (whether static or dynamic) it works in the same way.

Stefan

[Edited by ozzy - 10/16/2002 12:40:26 PM]

ozzy

Puff,

Why is the named pipes, multiprotocol thing down to static vs DHCP though?

We connect to SQL boxes over in BskyB from here and have never had any probs

Stefan

sillysi

Consultants have to earn their money someway My boss had trouble explaining the benefits of DHCP to me as he does not understand it anyway, it's a bit like The Office TV programme in my Dept.

ozzy

Cheers Carl

dsmith

You can of course manually configure certain MAC addresses to always get the same IP via DHCP.

You can combine the benefits of printers etc all having "static" ips with the benefits that if you need to change any of the details (IP, Default G/W , DNS etc etc) you can still do it centrally andjust power cylce the device to pick up new settings.

As to it making one jot of diff to perfomance once the IP address is learnt....errr... no.

Deano

Trotty

Heh heh heh, same here! I've got two weeks of my notice left and on Monday I'm supposed to start 'training' my boss - who's supposedly the 'IT Manager'! Pfft!...

Anyhoo, totaly agreeance with all of the above. DHCP can save you time with regards to general admin but it certainly can't have any impact/improvement with regards to network performance AFAIK.

Ian

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iTrader: (2)

Stefan

You misunderstood what I was saying.

Static/DHCP has no bearing on network preformance. However, depending on what network protocol you use (in this case IP) then having the correct SQL protocol between Server & client is important & although may work, say, on multiprotool, having named pipes may work better. Changed in the SQL Client utility. (As an example folks before I get flamed for the wrong SQL protocol for the network in question - I'm off duty atm!)

ozzy

Puff,

I didn't misunderstand you in regards to the performance issue. I just didn't understand why static vs DHCP has any bearing on SQL.

Wouldn't you just configure IP first (regardless of how it's allocated to the PC), then use the SQL client to configure whether you use IP or named pipes?

AFAIK, you could use named pipes regardless of whether you have a static or dynamic IP address as it's all contained in the client software (can only speak for Oracle though).

Stefan

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Stef

I never said static vs dhcp had any bearing on performance of SQL

I was offering the SQL named pipes/multiprotocol thing as a possible reason as to why Si's boss - who is not so computer literate - could be thinking that static vs dhcp did have some bearing, but Si's boss getting confused over what he heard maybe & hence spouting the incorrect assumption which is a mixture of both.

Its the only thing I could think of, given the scenario of IP (fixed/otherwise) and SQL being degraded in performance somehow, that might explain it.

ozzy

Right, now I follow you. Thought you'd lost the plot for a minute

Stefan

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danny-boy

For what its worth, I look after 6 servers, 50 odd workstations, I run 3 db's servers (SQL 6.5, 7 and Sybase) all Servers at NT4, and the workstations are 9x or 2k. I have my PDC running WINS and DHCP and have never had a bottle neck problem. The network is a mix of HP Procurve and 3Com.

Maybe if it you were dealing with thousands of external requests and internal request to the SQL server, having DHCP might make a very very slight difference but for a 100 users, I wouldnt worry.