From: Alexei Monastyrnyi (alexeim@orcsoftware.com)
Date: Thu Jul 26 2007 - 12:31:09 ART
Hi there.
It seems like IOS DHCP client does not request this option (12) from the
server. DocCD is a bit misleading here, or maybe it is me
misinterpreting it.
If on server side we have something like this:
ip dhcp pool FRS-DHCP
host 192.168.12.4 255.255.255.192
client-identifier cc1e
default-router 192.168.12.3
dns-server 172.16.12.33 172.16.12.34
client-name frs-dhcp
lease infinite
And on the client side something along these lines:
interface FastEthernet0/0
no ip dhcp client request netbios-nameserver
ip dhcp client client-id hex CC1E
ip address dhcp
The client requests the following options by default:
R3(config-if)#ip dhcp client request ?
dns-nameserver DNS nameserver (6)
domain-name Domain name (15)
netbios-nameserver NETBIOS nameserver (44)
router Default router option (3)
static-route Static route option (33)
tftp-server-address TFTP server address (150)
vendor-specific Vendor specific option (43)
<cr>
And snoop confirms it all but option 44, as per client's config:
DHCP: ----- (Options) field options -----
DHCP:
DHCP: Message type = DHCPREQUEST
DHCP: Maximum DHCP Message Size = 1152 bytes
DHCP: Client Identifier = 0xCC 0x1E (unprintable)
DHCP: DHCP Server Identifier = 192.168.12.1
DHCP: Requested IP Address = 192.168.12.4
DHCP: IP Address Lease Time = -1 seconds
DHCP: Client Hostname = R3
DHCP: Requested Options:
DHCP: 1 (Subnet Mask)
DHCP: 6 (DNS Servers)
DHCP: 15 (DNS Domain Name)
DHCP: 3 (Router)
DHCP: 33 (Static Routes)
DHCP: 150 (Site Option)
DHCP: 43 (Vendor Specific Options)
Here is what options are received, output from snoop:
DHCP: ----- (Options) field options -----
DHCP:
DHCP: Message type = DHCPACK
DHCP: DHCP Server Identifier = 192.168.12.1
DHCP: IP Address Lease Time = -1 seconds
DHCP: Renewal (T1) Time Value = 2147483647 seconds
DHCP: Rebinding (T2) Time Value = 536870911 seconds
DHCP: Subnet Mask = 255.255.255.192
DHCP: Router at = 192.168.12.3
DHCP: DNS Servers at = 172.16.12.33
DHCP: DNS Servers at = 172.16.12.34
DHCP: DNS Domain Name = cisco.com
And on the client we see:
*Jul 26 22:15:42.033: %DHCP-6-ADDRESS_ASSIGN: Interface FastEthernet0/0
assigned DHCP address 192.168.12.4, mask 255.255.255.192, hostname R3
So... no host name via DHCP for IOS clients, to my understanding. Not a
bigger loss though. :-)
HTH,
A.
on 7/26/2007 12:13 PM Bit Gossip wrote:
> In my setup I have a router getting its ip from a DHCP server R5 via DHCP and
> manual binding. It gets correctly the IP, mask, default-router and domain, but
> it doesn't get the hostname.
> Any suggestion:
>
> R5:
> ip dhcp pool POOL-R6
> host 155.1.146.66 255.255.255.128
> client-identifier
> 0063.6973.636f.2d30.3030.372e.6562.6263.2e62.3861.302d.4661.302f.30
> default-router 155.1.146.4
> domain-name cisco.com
> client-name R6
>
> *Mar 3 15:25:44.988: DHCPD: Sending notification of DISCOVER:
> *Mar 3 15:25:44.988: DHCPD: htype 1 chaddr 0007.ebbc.b8a0
> *Mar 3 15:25:44.988: DHCPD: circuit id 01f80000
> *Mar 3 15:25:44.988: DHCPD: DHCPDISCOVER received from client
> 0063.6973.636f.2d30.3030.372e.6562.6263.2e62.3861.302d.4661.302f.30 through
> relay 155.1.146.4.
> *Mar 3 15:25:44.988: DHCPD: Seeing if there is an internally specified pool
> class:
> *Mar 3 15:25:44.988: DHCPD: htype 1 chaddr 0007.ebbc.b8a0
> *Mar 3 15:25:44.988: DHCPD: circuit id 01f80000
> *Mar 3 15:25:44.992: DHCPD: Sending DHCPOFFER to client
> 0063.6973.636f.2d30.3030.372e.6562.6263.2e62.3861.302d.4661.302f.30
> (155.1.146.66).
> *Mar 3 15:25:44.992: DHCPD: unicasting BOOTREPLY for client 0007.ebbc.b8a0 to
> relay 155.1.146.4.
> *Mar 3 15:25:45.124: DHCPD: DHCPREQUEST received from client
> 0063.6973.636f.2d30.3030.372e.6562.6263.2e62.3861.302d.4661.302f.30.
> *Mar 3 15:25:45.124: DHCPD: Sending notification of ASSIGNMENT:
> *Mar 3 15:25:45.124: DHCPD: address 155.1.146.66 mask 255.255.255.128
> *Mar 3 15:25:45.124: DHCPD: lease time remaining (secs) = 4294967295
> *Mar 3 15:25:45.124: DHCPD: Appending default domain from pool
> *Mar 3 15:25:45.124: DHCPD: Using hostname 'Router.cisco.com.' for dynamic
> update (from hostname option)
> *Mar 3 15:25:45.124: DHCPD: Sending DHCPACK to client
> 0063.6973.636f.2d30.3030.372e.6562.6263.2e62.3861.302d.4661.302f.30
> (155.1.146.66).
> *Mar 3 15:25:45.128: DHCPD: unicasting BOOTREPLY for client 0007.ebbc.b8a0 to
> relay 155.1.146.4.
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Sat Aug 18 2007 - 08:17:42 ART