3 Replies Latest reply on Feb 7, 2014 9:28 AM by noor

    DHCP Addressing is painfully slow

    andyjo New Member

      So, i have a Netvanta 1534 as the only networking device in my system. My network consists of 5 Win 7 PCs, and the switch, completely separate from any other hardware.

      The problem i'm having is that it takes about 10-20 seconds for each host to obtain a DHCP address, and once they do the first time they start communicating it seems pretty slow (opening up a remote desktop between two, or accessing a shared folder for instance). Once the connection has been made it's pretty quick, i can see speeds upwards of 100mb/s, so, once everything is connected it's happy, it just takes forever for things to discover eachother...

      Is there any way (besides assigning static ip addresses) to make it 'fast'?

      I've also noticed that when connecting the whole system to my router it takes quite some time for system to get their DHCP addressing from the router, but if i plug everything into a dumb switch (5 port netgear), which it attached to my router, things are very very very fast...

      So i guess the other issue is that i have 3 configurations...

      The most important is in it's standalone configuration, where there is no other router/switch involved. It would be nice though to be able to plug a line in that goes over to 'real' router and grab addressing information from there and not have to wait so long for initialization... any thoughts?

      Also, i'm using the Web interface to change everything, as the only system i have with a serial port is not working...

      Just some background info: The reason network initialization matters so much is that we have some software that needs to talk asap, and the other reason is that windows mapped network drives like to 'try' to connect at log-in, and if the network connection is not established it fails, and i have to go through the pain of writing scripts to ping around the network before re-mapping the drives...

      I'll also preface that I'm just a systems engineer who was given a switch, and have no clue what i'm doing ;-)

       

      Here's my configuration:

      !

      !

      ! ADTRAN, Inc. OS version R10.5.1

      ! Boot ROM version 17.09.01.00

      ! Platform: NetVanta 1534, part number 1702590G1

      ! Serial number LBADTN1324AD317

      !

      !

      hostname "Switch"

      enable

      !

      clock timezone -5-Eastern-Time

      !

      ip subnet-zero

      ip classless

      ip default-gateway 10.10.10.1

      no ip routing

      domain-name "fld.remote"

      domain-proxy

      name-server 10.10.10.1

      !

      !

      no ip route-cache express

      !

      no auto-config

      !

      event-history on

      no logging forwarding

      no logging email

      !

      no service password-encryption

      !

      username "admin" password ""

      ip forward-protocol udp time

      ip forward-protocol udp nameserver

      ip forward-protocol udp tacacs

      ip forward-protocol udp tftp

      ip forward-protocol udp netbios-ns

      ip forward-protocol udp netbios-dgm

      !

      banner motd #

       

       

      #

      !

      !

      !

      !

      !

      !

      no dot11ap access-point-control

       

       

      no dos-protection

       

       

      no desktop-auditing dhcp

       

       

      no network-forensics ip dhcp

      !

      !

      !

      !

      ip dhcp excluded-address 10.10.10.1 10.10.10.2

      !

      ip dhcp pool "ProcNet"

        network 10.10.10.0 255.255.255.0

        domain-name "fld.remote"

        dns-server 10.10.10.1

        default-router 10.10.10.1

      !

      !

      !

      !

      !

      vlan 1

        name "Default"

      !

      interface port-channel 1

        description LAG1

        no shutdown

      !

      interface gigabit-switchport 0/1

        no shutdown

      !

      interface gigabit-switchport 0/2

        no shutdown

      !

      interface gigabit-switchport 0/3

        no shutdown

      !

      interface gigabit-switchport 0/4

        no shutdown

      !

      interface gigabit-switchport 0/5

        no shutdown

        switchport mode trunk

      !

      interface gigabit-switchport 0/6

        no shutdown

      !

      interface gigabit-switchport 0/7

        no shutdown

      !

      interface gigabit-switchport 0/8

        no shutdown

      !

      interface gigabit-switchport 0/9

        no shutdown

      !

      interface gigabit-switchport 0/10

        no shutdown

      !

      interface gigabit-switchport 0/11

        no shutdown

      !

      interface gigabit-switchport 0/12

        no shutdown

      !

      interface gigabit-switchport 0/13

        no shutdown

      !

      interface gigabit-switchport 0/14

        no shutdown

      !

      interface gigabit-switchport 0/15

        no shutdown

      !

      interface gigabit-switchport 0/16

        no shutdown

      !

      interface gigabit-switchport 0/17

        no shutdown

      !

      interface gigabit-switchport 0/18

        no shutdown

      !

      interface gigabit-switchport 0/19

        no shutdown

      !

      interface gigabit-switchport 0/20

        no shutdown

      !

      interface gigabit-switchport 0/21

        no shutdown

      !

      interface gigabit-switchport 0/22

        no shutdown

      !

      interface gigabit-switchport 0/23

        no shutdown

        channel-group 1 mode on

      !

      interface gigabit-switchport 0/24

        no shutdown

        channel-group 1 mode on

      !

      interface gigabit-switchport 0/25

        no shutdown

      !

      interface gigabit-switchport 0/26

        no shutdown

      !

      interface gigabit-switchport 0/27

        no shutdown

      !

      interface gigabit-switchport 0/28

        no shutdown

      !

      !

      !

      interface vlan 1

        ip address  10.10.10.1  255.255.255.0

        ip route-cache express

        no shutdown

      !

      !

      !

      !

      !

      no tftp server

      no tftp server overwrite

      http server

      http secure-server

      no snmp agent

      no ip ftp server

      ip ftp server default-filesystem flash

      no ip scp server

      no ip sntp server

      !

      !

      !

      !

      !

      !

      !

      !

      !

      line con 0

        no login

      !

      line telnet 0 4

        login

        password password

        no shutdown

      line ssh 0 4

        login local-userlist

        no shutdown

      !

      !

      !

      !

      end

       

      Message was edited by: andyjo

        • Re: DHCP Addressing is painfully slow
          Employee

          andyjo - Thanks for posting your question on the forum!

           

          My first guess is that spanning-tree maybe the reason it is taking some time for the network to initialize. Spanning-tree protocol (STP) is supposed to prevent loops from occurring on a bridged ethernet network. When a network topology change is detected (such as a new device being plugged in), STP will recalculate the best path. That calculation may be the reason the ports are taking some time to come up.

           

          To get around this, you may want to try setting those switchports that have end devices plugged in (PCs, phones) as an 'edgeport'. Ports with edgeport enabled do not wait for STP calculation to complete before they start forwarding traffic. In the GUI, you would need to navigate to Data-> Ports. There is a column labeled 'Edgeport Mode'. You would just to enable it on those ports that have end devices plugged into them. In the CLI, you would need to go into switchport configuration mode for the specific switchport and issue the "spanning-tree edgeport" command.

           

          Let us know if you have any questions.

           

          Thanks,

          Noor

            • Re: DHCP Addressing is painfully slow
              andyjo New Member

              Thanks noor,

              That really sped up EVERYTHING!

               

              Just to clarify, when i do have a router, or another network to connect to, the port i'm using should have edge-port disabled, and maybe be set to Trunk instead of a specific vlan? And when i do connect to another network, i should set all the ports to a vlan with an IP address or that of the network i'm attaching to?

              For instance, my home network is a 10.0.1.* network, my work network is a 192.168.0.* network. Does that imply i should create two more vlans on the switch, one for each network, then just blanket switch the ports when i connect to the other networks?

               

              Thanks!

              -Andy

                • Re: DHCP Addressing is painfully slow
                  Employee

                  andyjo - Edgeport should only be enabled on those ports that have end devices connected to them. There are situations where ports may be set up as trunks but have end devices connected to them. For example, a port may be set up as a trunk and have a phone plugged into it with a PC plugged into the phone's data port. However, any port that has another switch or router plugged in, I would recommend having edgeport disabled.

                   

                  You will want to set a port to trunk mode if you need multiple VLANs to go over that link. The following document may give you a better idea about VLANs and interVLAN routing: Configuring InterVLAN Routing in AOS - Quick Configuration Guide

                   

                  Please do not hesitate to let us know if you have any further questions.

                   

                  Thanks,

                  Noor