البته اینها به ذهنم رسیده بود ولی خوب یه ذره سیستم گیر میده که ای پی ها حتما باید در lease time پایین عوض بشن (ما از اون سیستمهای آفتابه لگن هفت دست شام و نهار هیچی هستیم)
راستی من dhcp رو روی سوییچ بردم. این قضیه ip to mac binding رو روی سوییچ تستکردید ؟ نمیدونم چرا برای من فقط برای یه هاست جواب میداد و تعداد بیشتری نمیشد ؟
فکر کنم یه مشکل دیگه هم بود اونم بحث option 61 اگه اشتباه نکنم که برای این کار باید روی سوییچ فعال میشد. ولی از اون طرف این فعالسازی باعث مشکل در dhcp snooping بین پروتهای ترانک (سوییچهای اکسس تا core ) میشد و باعث میشد سوییچهای اکسس نتونند از core ای پی بگیرن و به کلاینتها بدن
Configuring Manual Bindings
An address binding is a mapping between the IP address and MAC address of a client. The IP address of a client can be assigned manually by an administrator or assigned automatically from a pool by a DHCP server.
Manual bindings are IP addresses that have been manually mapped to the MAC addresses of hosts that are found in the DHCP database. Manual bindings are stored in NVRAM on the DHCP server. Manual bindings are just special address pools. There is no limit on the number of manual bindings, but you can only configure one manual binding per host pool.
Automatic bindings are IP addresses that have been automatically mapped to the MAC addresses of hosts that are found in the DHCP database. Automatic bindings are stored on a remote host called a database agent. The bindings are saved as text records for easy maintenance.
All DHCP clients send a client identifier (DHCP option 61) in the DHCP packet. To configure manual bindings, you must enter the client-identifier DHCP pool configuration command with the appropriate hexadecimal values identifying the DHCP client.
To configure a manual binding, first create a host pool, then specify the IP address of the client and client identifier or hardware address.
To configure manual bindings, use the following commands beginning in global configuration mode:
Command
Purpose
Step 1
Router(config)#
ip dhcp pool name
Creates a name for the a DHCP Server address pool and places you in DHCP pool configuration mode—identified by the (dhcp-config)# prompt.
Step 2
Router(dhcp-config)#
host address[
mask |
/prefix-length]
Specifies the IP address and subnet mask of the client.
The prefix length specifies the number of bits that comprise the address prefix. The prefix is an alternative way of specifying the network mask of the client. The prefix length must be preceded by a forward slash (/).
Step 3
Router(dhcp-config)#
client-identifier unique-identifier
Specifies the unique identifier for DHCP clients. This command is used for DHCP requests.
•
DHCP clients require client identifiers. The unique identification of the client is specified in dotted hexadecimal notation, for example, 01b7.0813.8811.66, where 01 represents the Ethernet media type.
•
See
"Troubleshooting Tips" below for information on how to determine the client identifier of the DHCP client.
Step 4
Router(dhcp-config)#
hardware-address hardware-addresstype
(Optional) Specifies a hardware address for the client. This command is used for BOOTP requests.
The
type value:
•
Indicates the protocol of the hardware platform. Strings and values are acceptable. The string options are:
–
ethernet
–
ieee802
•
The value options are:
–
1 10Mb Ethernet
–
6 IEEE 802
If no type is specified, the default protocol is Ethernet.
Step 5
Router(dhcp-config)#
client-name name
(Optional) Specifies the name of the client using any standard ASCII character. The client name should not include the domain name. For example, the name
mars should not be specified as
mars.cisco.com.
Troubleshooting Tips
You can determine the client identifier by using the debug ip dhcp server packet command. In the following example, the client is identified by the value 0b07.1134.a029.
Router# debug ip dhcp server packet
DHCPDHCPDISCOVER received from client 0b07.1134.a029 through relay 10.1.0.253.
DHCPD:assigned IP address 10.1.0.3 to client 0b07.1134.a029.
.