Re: Why not supernetting?
I couldn't agree more, a multiport switch connected to the router, then another switch for each area of worksations is the way I would go. Bri On Fri, 10 Nov 2000, Donald B Johnson Jr wrote: Your problem seems to be insufficient hardware. Supernetting five subnets and putting 500 stations on one segement will cripple your network. Duck - Original Message - From: jeongwoo park [EMAIL PROTECTED] To: Groupstudy [EMAIL PROTECTED] Sent: Wednesday, November 08, 2000 2:13 PM Subject: Why not supernetting? Hi All, I am looking for advice on a LAN performance issue. i am running primarily NT4 and win2K boxes on a 100Mbit UTP Ethernet LAN. my servers are on static IPs on one subnet while my clients pick up DHCP addresses (assigned out of my control) in any one of half a dozen other subnets. file transfer and printing performance between client and server is averaging 1Mbit/sec when computers are in different subnets. switch the same two computers to static IPs in the same subnet and throughput jumps to a respectable 30-70Mbit/sec. i need to keep the clients on DHCP as i don't have enough static IPs to go around for the subnet the servers are in. all clients and servers are attached to one of 5 Allied Telesyn 8126XL 24-port managed switches. all 5 of these "edge" switches connect to another switch of the same model with a 100Mbit multi-mode (1300 nanometer) fiber uplink which connects to a Cisco Catalyst 5500 for our routing needs. When the clients are on different subnets the file transfers appear to take a long trip through the router with a huge performance penalty (1Mbit/sec). when the client and server are on the same subnet the packets do NOT appear to be routed (perhaps they are handled using ARP?) and the performance is very good. ping response times on both switches and routers is under 20ms. This is where I believe supernetting could be a solution to this slowness, because I think supernetting allows me to put all stations in the same subnet, witch avoids routing needs. I got some responses to my previous post from people saying that supernetting would slow down the speed because there would be too many stations in big broadcast domain, which contradicts what I am willing to do. Am i missing some key concepts here that might improve my understanding of this tragic performance? any help would be greatly appreciated. take care, jw __ Do You Yahoo!? Thousands of Stores. Millions of Products. All in one Place. http://shopping.yahoo.com/ _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Why not supernetting?
You guys must be integrators! She has a 5500 already, which although somewhat dated, should be able to provide enough horsepower to route to 600 users in 5 or 6 subnets surely. I highly expect her issue is not lack of hardware related. I expect there is a misconfiguration or faulty cabling at some point along the line. Really, this type of troubleshooting is hard to do offline however :) *** REPLY SEPARATOR *** On 11/11/2000 at 3:25 PM Brian W. wrote: I couldn't agree more, a multiport switch connected to the router, then another switch for each area of worksations is the way I would go. Bri On Fri, 10 Nov 2000, Donald B Johnson Jr wrote: Your problem seems to be insufficient hardware. Supernetting five subnets and putting 500 stations on one segement will cripple your network. Duck - Original Message - From: jeongwoo park [EMAIL PROTECTED] To: Groupstudy [EMAIL PROTECTED] Sent: Wednesday, November 08, 2000 2:13 PM Subject: Why not supernetting? Hi All, I am looking for advice on a LAN performance issue. i am running primarily NT4 and win2K boxes on a 100Mbit UTP Ethernet LAN. my servers are on static IPs on one subnet while my clients pick up DHCP addresses (assigned out of my control) in any one of half a dozen other subnets. file transfer and printing performance between client and server is averaging 1Mbit/sec when computers are in different subnets. switch the same two computers to static IPs in the same subnet and throughput jumps to a respectable 30-70Mbit/sec. i need to keep the clients on DHCP as i don't have enough static IPs to go around for the subnet the servers are in. all clients and servers are attached to one of 5 Allied Telesyn 8126XL 24-port managed switches. all 5 of these "edge" switches connect to another switch of the same model with a 100Mbit multi-mode (1300 nanometer) fiber uplink which connects to a Cisco Catalyst 5500 for our routing needs. When the clients are on different subnets the file transfers appear to take a long trip through the router with a huge performance penalty (1Mbit/sec). when the client and server are on the same subnet the packets do NOT appear to be routed (perhaps they are handled using ARP?) and the performance is very good. ping response times on both switches and routers is under 20ms. This is where I believe supernetting could be a solution to this slowness, because I think supernetting allows me to put all stations in the same subnet, witch avoids routing needs. I got some responses to my previous post from people saying that supernetting would slow down the speed because there would be too many stations in big broadcast domain, which contradicts what I am willing to do. Am i missing some key concepts here that might improve my understanding of this tragic performance? any help would be greatly appreciated. take care, jw __ Do You Yahoo!? Thousands of Stores. Millions of Products. All in one Place. http://shopping.yahoo.com/ _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Why not supernetting?
You might think also to implement MLS (Multi Layer Switching) in your Catalyst 5500, after you have followed Peter recommendations. Sebastien. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Peter Van Oene Sent: 09 November 2000 00:14 To: [EMAIL PROTECTED] Subject: Re: Why not supernetting? Outside of anything more "best practice design" specific which others are and I'm sure will cover, I would look at your 100 meg downlinks (connections from edge switches to aggregation switches back to 5500 in increasing order of importance) Specifically, check to ensure that your duplexes on either end of the connections are set the same. Futher, look at error counts (crc's, runts etc) to ensure that these links are performing adequately. I've seen duplex mismatches cause exactly this type of "tragic" performance as you describe it. Peter *** REPLY SEPARATOR *** On 11/8/2000 at 2:13 PM jeongwoo park wrote: Hi All, I am looking for advice on a LAN performance issue. i am running primarily NT4 and win2K boxes on a 100Mbit UTP Ethernet LAN. my servers are on static IPs on one subnet while my clients pick up DHCP addresses (assigned out of my control) in any one of half a dozen other subnets. file transfer and printing performance between client and server is averaging 1Mbit/sec when computers are in different subnets. switch the same two computers to static IPs in the same subnet and throughput jumps to a respectable 30-70Mbit/sec. i need to keep the clients on DHCP as i don't have enough static IPs to go around for the subnet the servers are in. all clients and servers are attached to one of 5 Allied Telesyn 8126XL 24-port managed switches. all 5 of these "edge" switches connect to another switch of the same model with a 100Mbit multi-mode (1300 nanometer) fiber uplink which connects to a Cisco Catalyst 5500 for our routing needs. When the clients are on different subnets the file transfers appear to take a long trip through the router with a huge performance penalty (1Mbit/sec). when the client and server are on the same subnet the packets do NOT appear to be routed (perhaps they are handled using ARP?) and the performance is very good. ping response times on both switches and routers is under 20ms. This is where I believe supernetting could be a solution to this slowness, because I think supernetting allows me to put all stations in the same subnet, witch avoids routing needs. I got some responses to my previous post from people saying that supernetting would slow down the speed because there would be too many stations in big broadcast domain, which contradicts what I am willing to do. Am i missing some key concepts here that might improve my understanding of this tragic performance? any help would be greatly appreciated. take care, jw __ Do You Yahoo!? Thousands of Stores. Millions of Products. All in one Place. http://shopping.yahoo.com/ _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ Do You Yahoo!? Achetez, vendez! À votre prix! Sur http://encheres.yahoo.fr _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Why not supernetting?
Your problem seems to be insufficient hardware. Supernetting five subnets and putting 500 stations on one segement will cripple your network. Duck - Original Message - From: jeongwoo park [EMAIL PROTECTED] To: Groupstudy [EMAIL PROTECTED] Sent: Wednesday, November 08, 2000 2:13 PM Subject: Why not supernetting? Hi All, I am looking for advice on a LAN performance issue. i am running primarily NT4 and win2K boxes on a 100Mbit UTP Ethernet LAN. my servers are on static IPs on one subnet while my clients pick up DHCP addresses (assigned out of my control) in any one of half a dozen other subnets. file transfer and printing performance between client and server is averaging 1Mbit/sec when computers are in different subnets. switch the same two computers to static IPs in the same subnet and throughput jumps to a respectable 30-70Mbit/sec. i need to keep the clients on DHCP as i don't have enough static IPs to go around for the subnet the servers are in. all clients and servers are attached to one of 5 Allied Telesyn 8126XL 24-port managed switches. all 5 of these "edge" switches connect to another switch of the same model with a 100Mbit multi-mode (1300 nanometer) fiber uplink which connects to a Cisco Catalyst 5500 for our routing needs. When the clients are on different subnets the file transfers appear to take a long trip through the router with a huge performance penalty (1Mbit/sec). when the client and server are on the same subnet the packets do NOT appear to be routed (perhaps they are handled using ARP?) and the performance is very good. ping response times on both switches and routers is under 20ms. This is where I believe supernetting could be a solution to this slowness, because I think supernetting allows me to put all stations in the same subnet, witch avoids routing needs. I got some responses to my previous post from people saying that supernetting would slow down the speed because there would be too many stations in big broadcast domain, which contradicts what I am willing to do. Am i missing some key concepts here that might improve my understanding of this tragic performance? any help would be greatly appreciated. take care, jw __ Do You Yahoo!? Thousands of Stores. Millions of Products. All in one Place. http://shopping.yahoo.com/ _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Why not supernetting?
Just to be argumentative, it is not necessarily true that 500 hosts on a single network / wire will result in a crippled network. As always, it is the usage that will determine the result. I once interviewed with a very large bank. The network team there was required to have extensive protocol analysis expertise because, in the words of the interviewer, we have very large segments, and we want to eliminate problems as son as we hear about them. He told me they had as many as 1200 machines on a subnet! Obviously, in most circumstances, the network folks believed that performance was satisfactory. They did apparently spent a lot of time tracking down misbehaving NIC's :- Cisco's published recommendations about maximum hosts on a subnet / broadcast domain are general recommendations. I suggest that if you have folks doing extensive sharing of Autocad files, or extensive desktop video conferencing, or extensive VoIP, even the Cisco recommendations may be too large for reliable LAN performance. On the other hand, if all you are doing is SNA emulation. 500 may not be bad at all. Chuck -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Donald B Johnson Jr Sent: Friday, November 10, 2000 9:00 AM To: jeongwoo park; Groupstudy Subject:Re: Why not supernetting? Your problem seems to be insufficient hardware. Supernetting five subnets and putting 500 stations on one segement will cripple your network. Duck - Original Message - From: jeongwoo park [EMAIL PROTECTED] To: Groupstudy [EMAIL PROTECTED] Sent: Wednesday, November 08, 2000 2:13 PM Subject: Why not supernetting? Hi All, I am looking for advice on a LAN performance issue. i am running primarily NT4 and win2K boxes on a 100Mbit UTP Ethernet LAN. my servers are on static IPs on one subnet while my clients pick up DHCP addresses (assigned out of my control) in any one of half a dozen other subnets. file transfer and printing performance between client and server is averaging 1Mbit/sec when computers are in different subnets. switch the same two computers to static IPs in the same subnet and throughput jumps to a respectable 30-70Mbit/sec. i need to keep the clients on DHCP as i don't have enough static IPs to go around for the subnet the servers are in. all clients and servers are attached to one of 5 Allied Telesyn 8126XL 24-port managed switches. all 5 of these "edge" switches connect to another switch of the same model with a 100Mbit multi-mode (1300 nanometer) fiber uplink which connects to a Cisco Catalyst 5500 for our routing needs. When the clients are on different subnets the file transfers appear to take a long trip through the router with a huge performance penalty (1Mbit/sec). when the client and server are on the same subnet the packets do NOT appear to be routed (perhaps they are handled using ARP?) and the performance is very good. ping response times on both switches and routers is under 20ms. This is where I believe supernetting could be a solution to this slowness, because I think supernetting allows me to put all stations in the same subnet, witch avoids routing needs. I got some responses to my previous post from people saying that supernetting would slow down the speed because there would be too many stations in big broadcast domain, which contradicts what I am willing to do. Am i missing some key concepts here that might improve my understanding of this tragic performance? any help would be greatly appreciated. take care, jw __ Do You Yahoo!? Thousands of Stores. Millions of Products. All in one Place. http://shopping.yahoo.com/ _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Why not supernetting?
I second your arguments, Chuck. I worked on a scenario with varying subnet sizes due to some inherent limitations on how robots PLC's work (no default gateways). I had subnets of size 1024 with 500 machines on each subnet. PC traffic is difficult to predict because of human users but machines are predictible. Habeeb -Original Message- From: Chuck Larrieu [SMTP:[EMAIL PROTECTED]] Sent: Thursday, November 09, 2000 11:47 AM To: Donald B Johnson Jr; jeongwoo park; Groupstudy Subject: RE: Why not supernetting? Just to be argumentative, it is not necessarily true that 500 hosts on a single network / wire will result in a crippled network. As always, it is the usage that will determine the result. I once interviewed with a very large bank. The network team there was required to have extensive protocol analysis expertise because, in the words of the interviewer, we have very large segments, and we want to eliminate problems as son as we hear about them. He told me they had as many as 1200 machines on a subnet! Obviously, in most circumstances, the network folks believed that performance was satisfactory. They did apparently spent a lot of time tracking down misbehaving NIC's :- Cisco's published recommendations about maximum hosts on a subnet / broadcast domain are general recommendations. I suggest that if you have folks doing extensive sharing of Autocad files, or extensive desktop video conferencing, or extensive VoIP, even the Cisco recommendations may be too large for reliable LAN performance. On the other hand, if all you are doing is SNA emulation. 500 may not be bad at all. Chuck -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Donald B Johnson Jr Sent: Friday, November 10, 2000 9:00 AM To: jeongwoo park; Groupstudy Subject: Re: Why not supernetting? Your problem seems to be insufficient hardware. Supernetting five subnets and putting 500 stations on one segement will cripple your network. Duck - Original Message - From: jeongwoo park [EMAIL PROTECTED] To: Groupstudy [EMAIL PROTECTED] Sent: Wednesday, November 08, 2000 2:13 PM Subject: Why not supernetting? Hi All, I am looking for advice on a LAN performance issue. i am running primarily NT4 and win2K boxes on a 100Mbit UTP Ethernet LAN. my servers are on static IPs on one subnet while my clients pick up DHCP addresses (assigned out of my control) in any one of half a dozen other subnets. file transfer and printing performance between client and server is averaging 1Mbit/sec when computers are in different subnets. switch the same two computers to static IPs in the same subnet and throughput jumps to a respectable 30-70Mbit/sec. i need to keep the clients on DHCP as i don't have enough static IPs to go around for the subnet the servers are in. all clients and servers are attached to one of 5 Allied Telesyn 8126XL 24-port managed switches. all 5 of these "edge" switches connect to another switch of the same model with a 100Mbit multi-mode (1300 nanometer) fiber uplink which connects to a Cisco Catalyst 5500 for our routing needs. When the clients are on different subnets the file transfers appear to take a long trip through the router with a huge performance penalty (1Mbit/sec). when the client and server are on the same subnet the packets do NOT appear to be routed (perhaps they are handled using ARP?) and the performance is very good. ping response times on both switches and routers is under 20ms. This is where I believe supernetting could be a solution to this slowness, because I think supernetting allows me to put all stations in the same subnet, witch avoids routing needs. I got some responses to my previous post from people saying that supernetting would slow down the speed because there would be too many stations in big broadcast domain, which contradicts what I am willing to do. Am i missing some key concepts here that might improve my understanding of this tragic performance? any help would be greatly appreciated. take care, jw __ Do You Yahoo!? Thousands of Stores. Millions of Products. All in one Place. http://shopping.yahoo.com/ _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _
Re: Why not supernetting?
Yes we are using RSM for routing need. And I am not sure if we are using vlan because cat5500, and DHCP is out of my control. How can I verify if we are using vlan? It seems to me that we are using vlan because more than one subnet sits on the same physical edge switch, witch I am sure if it is correct way to verify if we are using vlan. I will appreciate your help jw --- Kevin Wigle [EMAIL PROTECTED] wrote: all 5 of these "edge" switches connect to another switch of the same model with a 100Mbit multi-mode (1300 nanometer) fiber uplink which connects to a Cisco Catalyst 5500 for our routing needs. hmmm... "connects to a Cisco Catalyst 5500 for our routing needs." How is the 5500 doing routing? Do you have vlans and a RSM (or MSFC) installed? Is there a real router here somewhere that is actually taking packets from one network and putting them on another? Are all the router interfaces 100 mbit? DHCP is out of your control? I'm afraid it sounds like you have bigger problems (layer 8). If whoever is doing this migration can't the DHCP I can't imagine how the project can succeed. You're giving us info little by little but still not enough to see your network. If you see good performance on a local subnet and degraded performance crossing subnets then whatever is between them is a bottleneck. Normally a Cat5500 shouldn't be that bottleneck especially if it's doing the routing (with a RSM/MSFC). Can you elaborate on how traffic is getting from one subnet to another? Kevin Wigle - Original Message - From: "jeongwoo park" [EMAIL PROTECTED] To: "Groupstudy" [EMAIL PROTECTED] Sent: Wednesday, 08 November, 2000 17:13 Subject: Why not supernetting? Hi All, I am looking for advice on a LAN performance issue. i am running primarily NT4 and win2K boxes on a 100Mbit UTP Ethernet LAN. my servers are on static IPs on one subnet while my clients pick up DHCP addresses (assigned out of my control) in any one of half a dozen other subnets. file transfer and printing performance between client and server is averaging 1Mbit/sec when computers are in different subnets. switch the same two computers to static IPs in the same subnet and throughput jumps to a respectable 30-70Mbit/sec. i need to keep the clients on DHCP as i don't have enough static IPs to go around for the subnet the servers are in. all clients and servers are attached to one of 5 Allied Telesyn 8126XL 24-port managed switches. all 5 of these "edge" switches connect to another switch of the same model with a 100Mbit multi-mode (1300 nanometer) fiber uplink which connects to a Cisco Catalyst 5500 for our routing needs. When the clients are on different subnets the file transfers appear to take a long trip through the router with a huge performance penalty (1Mbit/sec). when the client and server are on the same subnet the packets do NOT appear to be routed (perhaps they are handled using ARP?) and the performance is very good. ping response times on both switches and routers is under 20ms. This is where I believe supernetting could be a solution to this slowness, because I think supernetting allows me to put all stations in the same subnet, witch avoids routing needs. I got some responses to my previous post from people saying that supernetting would slow down the speed because there would be too many stations in big broadcast domain, which contradicts what I am willing to do. Am i missing some key concepts here that might improve my understanding of this tragic performance? any help would be greatly appreciated. take care, jw __ Do You Yahoo!? Thousands of Stores. Millions of Products. All in one Place. http://shopping.yahoo.com/ _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Why not supernetting?
Outside of anything more "best practice design" specific which others are and I'm sure will cover, I would look at your 100 meg downlinks (connections from edge switches to aggregation switches back to 5500 in increasing order of importance) Specifically, check to ensure that your duplexes on either end of the connections are set the same. Futher, look at error counts (crc's, runts etc) to ensure that these links are performing adequately. I've seen duplex mismatches cause exactly this type of "tragic" performance as you describe it. Peter *** REPLY SEPARATOR *** On 11/8/2000 at 2:13 PM jeongwoo park wrote: Hi All, I am looking for advice on a LAN performance issue. i am running primarily NT4 and win2K boxes on a 100Mbit UTP Ethernet LAN. my servers are on static IPs on one subnet while my clients pick up DHCP addresses (assigned out of my control) in any one of half a dozen other subnets. file transfer and printing performance between client and server is averaging 1Mbit/sec when computers are in different subnets. switch the same two computers to static IPs in the same subnet and throughput jumps to a respectable 30-70Mbit/sec. i need to keep the clients on DHCP as i don't have enough static IPs to go around for the subnet the servers are in. all clients and servers are attached to one of 5 Allied Telesyn 8126XL 24-port managed switches. all 5 of these "edge" switches connect to another switch of the same model with a 100Mbit multi-mode (1300 nanometer) fiber uplink which connects to a Cisco Catalyst 5500 for our routing needs. When the clients are on different subnets the file transfers appear to take a long trip through the router with a huge performance penalty (1Mbit/sec). when the client and server are on the same subnet the packets do NOT appear to be routed (perhaps they are handled using ARP?) and the performance is very good. ping response times on both switches and routers is under 20ms. This is where I believe supernetting could be a solution to this slowness, because I think supernetting allows me to put all stations in the same subnet, witch avoids routing needs. I got some responses to my previous post from people saying that supernetting would slow down the speed because there would be too many stations in big broadcast domain, which contradicts what I am willing to do. Am i missing some key concepts here that might improve my understanding of this tragic performance? any help would be greatly appreciated. take care, jw __ Do You Yahoo!? Thousands of Stores. Millions of Products. All in one Place. http://shopping.yahoo.com/ _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: Why not supernetting?
all 5 of these "edge" switches connect to another switch of the same model with a 100Mbit multi-mode (1300 nanometer) fiber uplink which connects to a Cisco Catalyst 5500 for our routing needs. hmmm... "connects to a Cisco Catalyst 5500 for our routing needs." How is the 5500 doing routing? Do you have vlans and a RSM (or MSFC) installed? Is there a real router here somewhere that is actually taking packets from one network and putting them on another? Are all the router interfaces 100 mbit? DHCP is out of your control? I'm afraid it sounds like you have bigger problems (layer 8). If whoever is doing this migration can't the DHCP I can't imagine how the project can succeed. You're giving us info little by little but still not enough to see your network. If you see good performance on a local subnet and degraded performance crossing subnets then whatever is between them is a bottleneck. Normally a Cat5500 shouldn't be that bottleneck especially if it's doing the routing (with a RSM/MSFC). Can you elaborate on how traffic is getting from one subnet to another? Kevin Wigle - Original Message - From: "jeongwoo park" [EMAIL PROTECTED] To: "Groupstudy" [EMAIL PROTECTED] Sent: Wednesday, 08 November, 2000 17:13 Subject: Why not supernetting? Hi All, I am looking for advice on a LAN performance issue. i am running primarily NT4 and win2K boxes on a 100Mbit UTP Ethernet LAN. my servers are on static IPs on one subnet while my clients pick up DHCP addresses (assigned out of my control) in any one of half a dozen other subnets. file transfer and printing performance between client and server is averaging 1Mbit/sec when computers are in different subnets. switch the same two computers to static IPs in the same subnet and throughput jumps to a respectable 30-70Mbit/sec. i need to keep the clients on DHCP as i don't have enough static IPs to go around for the subnet the servers are in. all clients and servers are attached to one of 5 Allied Telesyn 8126XL 24-port managed switches. all 5 of these "edge" switches connect to another switch of the same model with a 100Mbit multi-mode (1300 nanometer) fiber uplink which connects to a Cisco Catalyst 5500 for our routing needs. When the clients are on different subnets the file transfers appear to take a long trip through the router with a huge performance penalty (1Mbit/sec). when the client and server are on the same subnet the packets do NOT appear to be routed (perhaps they are handled using ARP?) and the performance is very good. ping response times on both switches and routers is under 20ms. This is where I believe supernetting could be a solution to this slowness, because I think supernetting allows me to put all stations in the same subnet, witch avoids routing needs. I got some responses to my previous post from people saying that supernetting would slow down the speed because there would be too many stations in big broadcast domain, which contradicts what I am willing to do. Am i missing some key concepts here that might improve my understanding of this tragic performance? any help would be greatly appreciated. take care, jw _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
