DHCP doesn't want to hand out DF and DNS on some hosts?

MrXpertMrXpert Member Posts: 586 ■■■□□□□□□□
hi,
I've started getting to grips with setting up dhcp services on a cisco router in PT. I also set up a dns server.
All seemed to be working fine but i noticed on SOME of my host pcs although they received an IP address and subnet mask via dhcp, they did not receive the Default gateway(DF) address nor the dns server IP. It seems some receive all the details but others dont. I have tried using the ipconfig /renew command as well as rebooting the hosts and router but no luck. I am able to ping from a host to the default gateway and back again. I have another subnet connected to this network and the PCs that have a DF can ping the other network but the PCs that dont have a DF can't. The big question on my mind is why are some PCs getting all the DHCP settings and others not? puzzled icon_sad.gif

Here's my running config. Help much appreciated.thanks

MOSCOW-R1#show run
Building configuration...

Current configuration : 1047 bytes
!
version 12.2
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname MOSCOW-R1
!
!
!
enable secret 5 $1$mERr$hx5rVt7rPNoS4wqbXKX7m0
!
!
ip dhcp excluded-address 172.16.0.254
ip dhcp excluded-address 172.16.0.1
ip dhcp excluded-address 172.16.0.2
!
ip dhcp pool MOSCOW
network 172.16.0.0 255.255.0.0
default-router 172.16.0.1
dns-server 172.16.0.254
!
!
!
!
!
!
!
ip domain-name moscow.com
ip host BOS-R1 192.168.0.1
ip name-server 172.16.0.254
!
!
!
!
!
!
interface FastEthernet0/0
ip address 172.16.0.1 255.255.0.0
duplex auto
speed auto
!
interface Serial0/0
description WAN
ip address 192.168.0.2 255.255.255.0
clock rate 800000
!
interface Serial0/1
no ip address
shutdown
!
ip classless
ip route 10.0.0.0 255.0.0.0 192.168.0.1
!
!
!
banner motd ^C
HI WELCOME TO MOSCOW ^C
!
!
!
!
line con 0
history size 20
exec-timeout 30 0
password 240478
logging synchronous
login
line vty 0 4
exec-timeout 222 0
password cisco1
logging synchronous
login
!
!
!
end
I'm an Xpert at nothing apart from remembering useless information that nobody else cares about.

Comments

  • MonkerzMonkerz Member Posts: 842
    Are the leases for the clients who do not receive DNS or GW info from DHCP, showing when you "show ip dhcp bindings"?

    Do you by chance have DHCP running on your switch as well, or anywhere else on the 172.16.0.0/16 network?

    Can you post your switch config too?
  • MrXpertMrXpert Member Posts: 586 ■■■□□□□□□□
    the lease command doesn't appear to work in PT.I have worked out though that the reason some pc's weren't getting the DFG IP is due to the fact they were added to the network (and ipconfig/renew run) before I configured the IP dhcp pool >default-router command (x.x.x.x). It seems PT doesnt like this, even if once i configured this command, rebooted the router and then added new PCs and used ipconfig/renew. If I dont configure this command and then try to do a ipconfig/renew it screws it all up even when i fixed it and added new pcs. I can only presume it is a problem with PT as i doubt a real cisco network would have this kind of weird issue? i set up another network today (a bigger one) which had routers in 4 different countries. All worked fine and they got the dhcp but this was because i configured the ip dhcp pool first.


    here is the running-config for the switch belonging to the network i had an issue with.

    MOSCOW-SWITCH#show run
    Building configuration...

    Current configuration : 1151 bytes
    !
    version 12.1
    no service timestamps log datetime msec
    no service timestamps debug datetime msec
    no service password-encryption
    !
    hostname MOSCOW-SWITCH
    !
    enable secret 5 $1$mERr$hx5rVt7rPNoS4wqbXKX7m0
    !
    ip host moscow-r1 172.16.0.1
    !
    !
    interface FastEthernet0/1
    !
    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 Vlan1
    ip address 172.16.0.2 255.255.0.0
    !
    ip default-gateway 172.16.0.1
    !
    !
    line con 0
    !
    line vty 0 4
    password cisco1
    logging synchronous
    login
    line vty 5 15
    password cisco1
    logging synchronous
    login
    !
    !
    end
    I'm an Xpert at nothing apart from remembering useless information that nobody else cares about.
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