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chfascik's avatar
Mar 09, 2017
Solved

M4100-D12G VLAN routing - ping VLAN1

Hi,

 

I have simple lab network:

netgear.jpg

 

Router, switch M4100, external DHCP server and 2 hosts.

I try to setup 2 VLANs and intervlan routing.

 

1. set static routing on router (172.16.5.1):

a) for VLAN 7: 172.16.7.0/24 GW: 172.16.5.254

b) for VLAN 8: 172.16.8.0/24 GW: 172.16.5.254

 

2. on switch M4100: move management VLAN to 500 so I have free VLAN 1 and can set routing

a) set VLAN 7 and VLAN 8. Add port to VLAN: port 7 to VLAN 7, Untagged. Add port to VLAN: port 8 to VLAN 8 Untagged. Add port 1 (uplink to router) Tagged for VLAN 7 and 8. Add port 2 Tagged for VLAN 7 and 8.

b) set VLAN routing and routing table - screenshot below

1routing.png

2_vlanrouting.png

3. Set DHCP relay (UDP relay) on switch to 172.16.5.2 and set DHCP Pool for VLAN7 and VLAN8 on external DHCP server.

 

And now....

1. Hosts in VLAN 7, 8 get IP from DHCP, get DNS, get GW

2. Hosts in VLAN 7 and VLAN 8 ping each other and ping VLAN 7 and VLAN 8 interface

3. Hosts in VLAN 7 and VLAN 8 have access to internet

4. Hosts in VLAN 1 ping hosts in VLAN 7 nad VLAN 8.

5. Hosts in VLAN 7 and 8 can ping VLAN 1 addresses but only: 172.16.5.1 (router/gateway) and VLAN1 interface (172.16.5.254). When I try to ping DHCP 172.16.5.2 i had request timed out.

 

What I forgot to do or what done wrong? ;-)

 

 

  • Hi chfascik,

     

    Kindly click on this article and it might help.  Kindly use it as your guide.

     

     

    Regards,

     

    DaneA

    NETGEAR Community Team

8 Replies

  • DaneA's avatar
    DaneA
    NETGEAR Employee Retired

    Hi chfascik,

     

    Kindly click on this article and it might help.  Kindly use it as your guide.

     

     

    Regards,

     

    DaneA

    NETGEAR Community Team

    • chfascik's avatar
      chfascik
      Tutor

      DaneA wrote:

      Hi chfascik,

       

      Kindly click on this article and it might help.  Kindly use it as your guide.

       

       

      Regards,

       

      DaneA

      NETGEAR Community Team


      thanks DaneA - I'll try to read and configure it.

    • chfascik's avatar
      chfascik
      Tutor

      DaneA wrote:

      Hi chfascik,

       

      Kindly click on this article and it might help.  Kindly use it as your guide.

       

       

      Regards,

       

      DaneA

      NETGEAR Community Team


      DaneA I made exactly the same configuration as described in Your link.

       

      Setup VLAN routing

      Setup static routing

      Setup default route

      Setup DHCP server.

       

      1. DCHP server (located in vlan 1) give IP addresses to all VLAN7 and VLAN8 clients.

      2. I can ping from VLAN 1 to VLAN 7 and 8 VLAN interface and clients

      3. I can ping from VLAN 7 to VLAN 8 VLAN interface and clients

      4. I can ping from VLAN 7 to VLAN 1 interface (172.16.5.254)

      5. I can ping from VLAN 7 to router/gateway (172.16.5.1) located in VLAN 1

      6. I can't ping any host conncted to VLAN 1 on switch.

      7. I can ping from VLAN 7 WiFi clients connected to router (client addresses 172.16.5.x/24).

       

      There is only problem with traffic from VLAN 7 and 8 to VLAN 1 clients connected to VLAN 1 on switch ports.

       

      try to do that on M4100-d12g and M4100-26G. The same resault. :(

      • chfascik's avatar
        chfascik
        Tutor

        Sorry for forum spam but I solved the problem.

        What was wrong? Gateway IP address on DHCP server for VLAN 1 and on all clients connected to switch to VLAN 1 ports. So I have to change Default Gateway for 172.16.5.x/24 network from 172.16.5.1 to 172.16.5.254 and now works fine.

         

        thanks for You for Your help and directinons :)

  • Not sure which was your question about ping.. but I assume you meant.

     

    Hosts in VLAN 7 and 8 can ping VLAN 1 addresses but only: 172.16.5.1 (router/gateway) and VLAN1 interface (172.16.5.254). When I try to ping DHCP 172.16.5.2 i had request timed out.

     

    Ping is not really a switch issue here.  Ping within vlan or across vlan uses the same principal here.  Verify the ARP table shows entry for 172.16.5.2 on vlan.  Additionaly you are able to get DHCP from that server on VLAN 7 and 8 indicating clearly that you have communication possibility from the server to VLAN 1 (relay agent is switch VLAN 1 routing address since your server is on VLAN 1)

     

    show arp 

     

    If ARP is there then ping is being blocked at the server level.  Since you can reach both the gateway and vlan 1 interface from other VLAN but not the DHCP, you issue will then likely be limited to 1 of following:

    1. Your server has firewall that only trust the VLAN 1 network or block ICMP incoming

    2. You have mis configured the whole thing.. see below for basic implemetation.

     

    Also, you don't need the move management VLAN to 500 in order to use VLAN 1.  You can configure routing on VLAN 1 interface, by default all routing interface will allow access to Switch via telnet, ssh, http, https.  You will need to configure ACL to limit access to specific source address only if you want to prevent this.

     

    Here is sample configuration to help you out based on diagram you provided.  You can clear config and paste this to enable prompt on the switch via USB or serial console if you like.  Or download the txt configuration and read it and see what you did wrong, or pm it to me and I will correct it.  !!! are comments

     

    !!! We create vlan and enable routing on them

    vlan database

    vlan 1, 7, 8

    vlan routing 1

    vlan routing 7

    vlan routing 8

    exit

    !!! enter global config mode

    config

    !!! enable DHCP relay UDP ip helper service

    ip helper enable

    !!! enable global routing which can be static or rip or ospf or bgp depending on switch

    ip routing

    !!! add default route to send all traffic to firewall router for internet

    ip route 0.0.0.0 0.0.0.0 172.16.5.1

    !!! configure vlan 1 routing interface

    interface vlan 1

    ip address 172.16.5.254 255.255.255.0

    exit

    !!! configure vlan 7 and enable dhcp request to be relayed to dhcp server for this vlan only

    interface vlan 7

    ip address 172.16.7.254 255.255.255.0

    ip helper-address 172.16.5.2 dhcp

    exit

    !!! configure vlan 8 and enable dhcp request to be relayed to dhcp server for this vlan only

    interface vlan 8

    ip address 172.16.8.254 255.255.255.0

    ip helper-address 172.16.5.2 dhcp

    exit

    !!! configure interface port 1 to vlan 1 which is your internet and dhcp vlan at this time.  No need to tag it for other vlan as router won't know how to treat that data instead it should be routed to router address by switch

     

     

    interface 0/1

    description "Port to Router"

    vlan pvid 1

    vlan participation include 1

    exit

     

    !!! DHCP does not need to vlan 7 or 8.  DHCP UDP relay service on switch will send DHCP request via routing from source 172.16.5.254 address to the dhcp server.  the server will then send the offer packet via relay address 172.16.5.254.  As such the dhcp server does not need to be present on vlan 7 or 8 locally.

     

    interface 0/2

    description "Port to DHCP Server"

    vlan pvid 1

    vlan participation include 1

    exit

     

    interface 0/7

    description "access port vlan 7"

    vlan pvid 7

    vlan participation include 7

    vlan participation exclude 1

    exit

     

    interface 0/8

    description "access port vlan 8"

    vlan pvid 8

    vlan participation include 8

    vlan participation exclude 1

    exit

     

    exit

    save

    y

     

    _-----------------------------------_

    Now log into your firewall Router and configure a static Routes for VLAN 7 and 8 to send traffic back to switch.  Since the firewall is 172.16.5.1 it need to send traffic to 172.16.5.2 when the destination IP is either vlan 7 or 8.   On the Switch we are sending all traffic to firewall when the destination is not 5.x , 7.x, or 8.x

     

    Network | Mask | Gateway

    172.16.7.0 255.255.255.0 172.16.5.2

    172.16.8.0 255.255.255.0 172.16.5.2

     

    _-----------------------------------_

    Log into your DHCP and create a pool for VLAN 7 and 8 with Gateway value of 172.16.x.254 where x is 7 or 8 depending on pool.  DNS can be whatever you have.

     

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

    You don't need to do tagging of VLAN 7 or 8 or participation of those vlan to get internet to those vlan and this is now taken care of by routing.   You can tag the port going to another switch for vlan 7 and 8 if you are creating a trunk link where the other switch is aware of vlan 7 and 8 and will have ports for those vlans.  See example below.  The other switch will need to have vlan capable.   Plus and above switches can do basic vlans.

     

    interface 0/6

    description "Trunk port to another vlan aware switch"

    vlan participation include 1,7,8

    vlan tagging 7,8

    exit

     

     

     

    Hope this is useful.

     

    • chfascik's avatar
      chfascik
      Tutor

      Jedi_Exile - thanks for reply.

       

      I made configuration as You described. Here is the show running-config. I add only VLAN 7 and change uplink ports (port1 is to DHCP, port 26 is uplink to router). Change switch to M1400-26G.

       

      Of course interface 0/1 is:

      interface 0/1

      vlan pvid 1

      vlan participation include 1

       

      vlan database
      vlan 7
      vlan routing 1 1
      vlan routing 7 3
      exit
      
      configure
      time-range
      ip route 0.0.0.0 0.0.0.0 172.16.5.1
      ip helper enable
      ip helper-address 172.16.5.2 dhcp
      line console
      exit
      
      line telnet
      exit
      
      line ssh
      exit
      
      !
      
      interface 0/1
      description 'Port to DHCP Server'
      exit
      
      interface 0/7
      description 'access port vlan 7'
      vlan pvid 7
      vlan participation exclude 1
      vlan participation include 7
      exit
      
      interface 0/26
      description 'Port to Router'
      exit
      
      interface vlan 1
      routing
      ip address 172.16.5.254 255.255.255.0
      exit
      
      interface vlan 7
      routing
      ip address 172.16.7.254 255.255.255.0
      exit
      
      service dhcp
      exit

      Also I changed router and DHCP server configuration.

      Here is static routes on router

      router.png

       

      And DHCP server settings

      nas.png

      and if I done that host in VLAN 7 can't get IP address. From VLAN 7 host I can't ping any host in VLAN 1 (gateway, clients, DHCP server).

       

      and here is "show arp" from switch:

      ;

      (M4100-26G) #show arp
      
      Age Time (seconds)............................. 1200
      Response Time (seconds)........................ 10
      Retries........................................ 10
      Cache Size..................................... 509
      Dynamic Renew Mode ............................ Enable
      Total Entry Count Current / Peak .............. 7 / 7
      Static Entry Count Configured / Active / Max .. 0 / 0 / 16
      
        IP Address        MAC Address      Interface        Type        Age
      ---------------  -----------------  --------------  --------  -----------
      172.16.5.1       00:11:32:72:34:B4  vlan 1          Gateway    0h  0m 19s
      172.16.5.2       00:11:32:55:A3:1E  vlan 1          Dynamic    0h  3m 57s
      172.16.5.40      00:00:00:00:00:00  vlan 1          Dynamic    0h  0m  4s
      172.16.5.41      E4:A4:71:90:95:A2  vlan 1          Dynamic    0h  0m 52s
      172.16.5.254     C0:FF:D4:AC:67:98  vlan 1          Local         n/a
      172.16.7.2       C8:5B:76:3A:2F:ED  vlan 7          Dynamic    0h  0m  4s
      172.16.7.254     C0:FF:D4:AC:67:98  vlan 7          Local         n/a

       

       And if I changed static route Gateway to 172.16.7.254 for VLAN 7 I can ping gateway 172.16.5.1 and other host in VLAN1 (172.16.5.0/24) but not 172.16.5.2 (I disabled firewall on DHCP server).

       

      • chfascik's avatar
        chfascik
        Tutor

        ... error. Can ping from VLAN7 only hosts in VLAN1 which are connected to router (gateway) WiFi :( When I connect host to M4100 to VLAN 1 I can't ping it from VLAN 7

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