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VLAN and Routing performance issues

I have a small problem here, but first some background on my network...

I have several VLANS setup on a switch (WS-C3548-XL-EN) as follows: VLAN 10 is for network devices (Internet router, core router, etc.) VLAN 100 is for servers VLAN 200 is for workstations VLAN 210 is for wireless.

Various ports on the switch are tagged for their respective VLANS. Fa0/1 is set as the trunk to the 2621.

Now when I am copying large files between a workstation (on workstation vlan) and my fileserver (on server vlan) I seem to notice that the Internet connectivity hiccups. It doesn't exactly go down until the transfer is done, but it does seem to lag a great deal in small bursts.

Now I seem to think this may be an issue with the fact that my core router (the 2621) cannot handle all the packets on the trunk interface to it. (trying to route between the workstation and server vlan, while also routing between workstation vlan and network devices vlan).

I guess after that description of my situation, my question would be either or both of the following:

  1. Is there a way to implement some QoS on the switch or router to ensure the copies from workstations to servers don't kill the available throughput?
  2. Is there any chance that switching from ISL to .1Q vlans would make any difference (no I am not using, nor plan to use, anything other than cisco gear)

Any help would be greatly appreciated! Especially any sample config changes!

Below is a copy of my configs...

INTERNET----(CISCO 871)-----(CISCO 2621)-----(CISCO 3548)-----LAN

************************************************************************************************************ ************************************************************************************************************ Cisco 2621: ************************************************************************************************************ ************************************************************************************************************

corertr#show run Building configuration...

Current configuration : 1492 bytes ! version 12.3 service timestamps debug datetime msec service timestamps log datetime msec service password-encryption ! hostname corertr ! boot-start-marker boot-end-marker ! enable secret 5 [Ommited] enable password 7 [Ommited] ! no aaa new-model ip subnet-zero ip cef ! ! ip domain name edgenet.local ip name-server 172.16.1.10 ip name-server 172.16.1.11 ! ip audit po max-events 100 ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! interface FastEthernet0/0 ip address 10.0.0.2 255.255.255.252 duplex auto speed auto ! interface FastEthernet0/1 no ip address duplex auto speed auto ! interface FastEthernet0/1.10 encapsulation isl 10 ip address 10.1.1.1 255.255.255.0 no ip redirects no snmp trap link-status ! interface FastEthernet0/1.100 encapsulation isl 100 ip address 172.16.1.1 255.255.255.0 no ip redirects no snmp trap link-status ! interface FastEthernet0/1.200 encapsulation isl 200 ip address 172.16.200.1 255.255.255.0 ip helper-address 172.16.1.10 no ip redirects no snmp trap link-status ! interface FastEthernet0/1.210 encapsulation isl 210 ip address 172.16.210.1 255.255.255.0 ip helper-address 172.16.1.10 no ip redirects no snmp trap link-status ! router rip network 10.0.0.0 network 172.16.0.0 ! no ip http server no ip http secure-server ip classless ip route 0.0.0.0 0.0.0.0 10.0.0.1 ! ! logging 172.16.1.7 ! snmp-server community public RO ! ! ! ! ! line con 0 line aux 0 line vty 0 4 password 7 [Ommited] login ! ! end

corertr#

************************************************************************************************************ ************************************************************************************************************ Cisco 3548: ************************************************************************************************************ ************************************************************************************************************

coreswitch#show run Building configuration...

Current configuration: ! version 12.0 no service pad service timestamps debug uptime service timestamps log uptime service password-encryption ! hostname coreswitch ! enable secret 5 [Ommited] enable password 7 [Ommited] ! ! ! ! ! clock timezone EST -5 ! ip subnet-zero ip domain-name edgenet.local ip name-server 172.16.1.10 ip name-server 172.16.1.11 ! ! ! interface FastEthernet0/1 description TRUNK TO CORE ROUTER switchport trunk allowed vlan 1,10,100,200,210,1002-1005 switchport mode trunk ! interface FastEthernet0/2 ! interface FastEthernet0/3 ! interface FastEthernet0/4 ! interface FastEthernet0/5 ! interface FastEthernet0/6 ! interface FastEthernet0/7 ! interface FastEthernet0/8 ! interface FastEthernet0/9 ! interface FastEthernet0/10 ! interface FastEthernet0/11 ! interface FastEthernet0/12 ! interface FastEthernet0/13 ! interface FastEthernet0/14 ! interface FastEthernet0/15 ! interface FastEthernet0/16 ! interface FastEthernet0/17 ! interface FastEthernet0/18 ! interface FastEthernet0/19 ! interface FastEthernet0/20 ! interface FastEthernet0/21 ! interface FastEthernet0/22 ! interface FastEthernet0/23 ! interface FastEthernet0/24 ! interface FastEthernet0/25 ! interface FastEthernet0/26 switchport access vlan 200 ! interface FastEthernet0/27 switchport access vlan 200 ! interface FastEthernet0/28 switchport access vlan 200 ! interface FastEthernet0/29 switchport access vlan 200 ! interface FastEthernet0/30 switchport access vlan 200 ! interface FastEthernet0/31 switchport access vlan 200 ! interface FastEthernet0/32 switchport access vlan 200 ! interface FastEthernet0/33 switchport access vlan 210 ! interface FastEthernet0/34 switchport access vlan 210 ! interface FastEthernet0/35 ! interface FastEthernet0/36 ! interface FastEthernet0/37 ! interface FastEthernet0/38 ! interface FastEthernet0/39 ! interface FastEthernet0/40 ! interface FastEthernet0/41 ! interface FastEthernet0/42 ! interface FastEthernet0/43 ! interface FastEthernet0/44 switchport access vlan 100 ! interface FastEthernet0/45 switchport access vlan 100 ! interface FastEthernet0/46 switchport access vlan 100 ! interface FastEthernet0/47 switchport access vlan 100 ! interface FastEthernet0/48 switchport access vlan 100 ! interface GigabitEthernet0/1 ! interface GigabitEthernet0/2 ! interface VLAN1 no ip address no ip directed-broadcast no ip route-cache shutdown ! interface VLAN10 ip address 10.1.1.249 255.255.255.0 no ip directed-broadcast no ip route-cache ! ip default-gateway 10.1.1.1 no ip http server snmp-server engineID local 00000009020000046DF94F00 snmp-server community public RO ! line con 0 login transport input none stopbits 1 line vty 0 4 password 7 [Ommited] login line vty 5 15 password 7 [Ommited] login ! end

coreswitch# coreswitch# coreswitch# coreswitch#show vlan VLAN Name Status Ports

---- -------------------------------- ---------

-------------------------------

1 default active Fa0/2, Fa0/3, Fa0/4, Fa0/5, Fa0/6, Fa0/7, Fa0/8, Fa0/9, Fa0/10, Fa0/11, Fa0/12, Fa0/13, Fa0/14, Fa0/15, Fa0/16, Fa0/17, Fa0/18, Fa0/19, Fa0/20, Fa0/21, Fa0/22, Fa0/23, Fa0/24, Fa0/25, Fa0/35, Fa0/36, Fa0/37, Fa0/38, Fa0/39, Fa0/40, Fa0/41, Fa0/42, Fa0/43, Gi0/1, Gi0/2 10 network_devices_vlan active 100 server_vlan active Fa0/44, Fa0/45, Fa0/46, Fa0/47, Fa0/48 200 workstation_vlan active Fa0/26, Fa0/27, Fa0/28, Fa0/29, Fa0/30, Fa0/31, Fa0/32 210 wireless_vlan active Fa0/33, Fa0/34 1002 fddi-default active 1003 token-ring-default active 1004 fddinet-default active 1005 trnet-default active

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2

---- ----- ---------- ----- ------ ------ -------- ---- -------- ------

------

1 enet 100001 1500 - - - - - 0 0 10 enet 100010 1500 - - - - - 0 0 100 enet 100100 1500 - - - - - 0 0 200 enet 100200 1500 - - - - - 0 0 210 enet 100210 1500 - - - - - 0 0 1002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0 coreswitch#
Reply to
Edward Salonia
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any difference (no I am not using, nor plan to use, anything other than cisco gear)

No - though you might as well switch to DOT1Q trunking if you have the time. Even Cisco now recommends DOT1Q simply from a standards perspective.

WRT your problem, is CEF enabled on the 2621 FE interface to which this traffic is trunked? Hopefully it is. Can you get on the router and sh proc and sh int fa n/n while the file transfer is running to determine whether you are having a bandwidth issue on the FE port or a processing issue on the router (especially if CEF is not enabled) ? Make sure the interface isn't throwing errors either. Since both interfaces are fastethernet, you should hardcode them to 100/full on both switch and router. You may be negotiating to only 10/half which could be the cause of your issues as well.

I'm presuming your 3548 does not have an enterprise license to allow it to create more than one active VLAN interface. If it did you should be routing internally traffic there.

Good luck! Jason

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Reply to
jseemann

Also, you seem to be trunking VLANS on your switch that you are not using, like 1002-1005, and also VLAN 1, which you are not using. Make sure everything matches up at either end.

Regards

snipped-for-privacy@gmail.com wrote:

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Reply to
James

Well, Actually, I think the switch is running enterprise software:

coreswitch#show ver Cisco Internetwork Operating System Software IOS (tm) C3500XL Software (C3500XL-C3H2S-M), Version 12.0(5)WC16, RELEASE SOFTWA RE (fc1) Copyright (c) 1986-2006 by cisco Systems, Inc. Compiled Thu 21-Sep-06 12:51 by antonino Image text-base: 0x00003000, data-base: 0x00352924

ROM: Bootstrap program is C3500XL boot loader

coreswitch uptime is 1 week, 18 hours, 5 minutes System returned to ROM by power-on System image file is "flash:c3500xl-c3h2s-mz.120-5.WC16.bin"

cisco WS-C3548-XL (PowerPC403) processor (revision 0x01) with

16384K/1024K bytes of memory. Processor board ID FAA0449I0JG, with hardware revision 0x00 Last reset from power-on

Processor is running Enterprise Edition Software Cluster command switch capable Cluster member switch capable

48 FastEthernet/IEEE 802.3 interface(s) 2 Gigabit Ethernet/IEEE 802.3 interface(s)

32K bytes of flash-simulated non-volatile configuration memory. Base ethernet MAC Address: 00:04:6D:F9:4F:00 Motherboard assembly number: 73-3903-07 Motherboard serial number: [Omitted] Power supply serial number: NONE Model revision number: A0 Motherboard revision number: B0 Model number: WS-C3548-XL-EN System serial number: [Omitted] Configuration register is 0xF

coreswitch#

Now if that is the enterprise you are talking about, how would I go about setting up what you are referring to? I am not quite clear on this. My experience with VLANS is rather limited (if you couldn't tell already).

And with regards to CEF. I have absolutely no experience with this. Would I just need to do "ip cef accounting..." on the router interface that is connected to the trunk?

Also, those vlans that were trunked that weren't in use (1, 1002-1005), it added those by default. Not sure why, but I will remove them.

Thanks for your time!

-- Ed

James wrote:

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Reply to
Edward Salonia

Hi Ed,

After looking at the specified configuration and Sh ver output I assume that the switch has layer-3 Capabilities and you may consider it for Inter VLAN routing. Currently for inter VLAN routing you are using

2621 router which does not seems to be a good choice if you have enough resources. Also I am not sure whether you would require 2621 router if 3548 have layer -3 functionality. In a layer 3 switch by default inter VLAN routing is enabled and there is no need for specific configuration. Also you would be getting 100 MBPS speed for all the VLANs for inter VLAN. Communication. On 2621 currently you are using 100 MBPS FastEthernet0/1 interface for Internet connectivity and Inter VLAN communication. So Internet traffic is getting effected once the Inter VLAN communication is taking place, since interface FastEthernet0/1 is used for Inter VLAN and taking traffic to 871 router (Internet router).

  1. You are using 2621 for two purposes to connect to internet router

871 and for inter VLAN routing.

  1. You may remove 2621 router and terminate 871 directly to 3548. On

3548 switch create a separate VLAN (for example VLAN 220) and assign it to switch port to which 871 is terminated.

  1. Later on create a VLAN 100, 200, 210 in the 3548 switch and assign the IP address within the subnet. You can also use the IP address already used in 2621 (after removing router 2621).

  2. Create a VLAN 220 and assign an IP address 10.0.0.2 (after removing router 2621).

5.On 3548 Switch specify IP-helper address on VLAN 100, 200, 210 for DHCP relay agent, also specify IP name-server and IP domain name.

  1. On 3548 router enter a default route for destination 10.0.0.1.

Please let me know if you have any question in this regard.

Thank you,

Deepak

Edward Sal> Well, Actually, I think the switch is running enterprise software: >

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Reply to
Cisco_Solutions

The 3548XL is not an L3 switch.

Reply to
Drake

So what is the verdict? Still not quite sure myself. I would imagine it has some L3 functionality, though just not sure on how to config it properly

Reply to
Edward Salonia

The 3548XL is not an L3 switch. It can *not* route between VLANs. You can't assign more than 1 IP address to the 3548, and this IP address can only be used for management purposes.

If you want a switch which can also route, you need at least a 3550 or

3560.

Steinar Haug, Nethelp consulting, snipped-for-privacy@nethelp.no

Reply to
Steinar Haug

Ok,

Thank you.

Reply to
Edward Salonia

All of my problems were fixed with one simple command on the physical interface (the one containing all the VLAN sub-if's on the corertr):

random-detect dscp-based

No more timeouts or transit delays...

:)

Reply to
Edward Salonia

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