How can I recreate a unique identifier for DHCP in Ubuntu 18.04?
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Following up from this question: Wrong IP address from DHCP client on Ubuntu 18.04
.
The TL;DR version of the question above is that Ubuntu has changed from identifying itself to DHCP servers with the MAC address to a unique identifier (presumably) generated when the OS is installed. The solution is to change a config file to restore the old behaviour.
I recently ran into this behaviour when working with a set of VirtualBox VMs. I was working on a project involving communications between a set of servers, so I set up a "base" server with the software I needed then cloned it multiple times. Of course, each cloned server had the same identifier, so they all received the same IP address from our DHCP server.
The answer to the question above solved the problem, but it left me wondering: How can I change the identifier assigned when Ubuntu is installed?
networking ubuntu dhcp
asked Dec 3 at 16:52
Kryten
21114
add a comment |
up vote
0
down vote
favorite
Following up from this question: Wrong IP address from DHCP client on Ubuntu 18.04
.
The TL;DR version of the question above is that Ubuntu has changed from identifying itself to DHCP servers with the MAC address to a unique identifier (presumably) generated when the OS is installed. The solution is to change a config file to restore the old behaviour.
I recently ran into this behaviour when working with a set of VirtualBox VMs. I was working on a project involving communications between a set of servers, so I set up a "base" server with the software I needed then cloned it multiple times. Of course, each cloned server had the same identifier, so they all received the same IP address from our DHCP server.
The answer to the question above solved the problem, but it left me wondering: How can I change the identifier assigned when Ubuntu is installed?
networking ubuntu dhcp
asked Dec 3 at 16:52
Kryten
21114
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
Following up from this question: Wrong IP address from DHCP client on Ubuntu 18.04
.
The TL;DR version of the question above is that Ubuntu has changed from identifying itself to DHCP servers with the MAC address to a unique identifier (presumably) generated when the OS is installed. The solution is to change a config file to restore the old behaviour.
I recently ran into this behaviour when working with a set of VirtualBox VMs. I was working on a project involving communications between a set of servers, so I set up a "base" server with the software I needed then cloned it multiple times. Of course, each cloned server had the same identifier, so they all received the same IP address from our DHCP server.
The answer to the question above solved the problem, but it left me wondering: How can I change the identifier assigned when Ubuntu is installed?
networking ubuntu dhcp
asked Dec 3 at 16:52
Kryten
21114
Following up from this question: Wrong IP address from DHCP client on Ubuntu 18.04
.
The TL;DR version of the question above is that Ubuntu has changed from identifying itself to DHCP servers with the MAC address to a unique identifier (presumably) generated when the OS is installed. The solution is to change a config file to restore the old behaviour.
I recently ran into this behaviour when working with a set of VirtualBox VMs. I was working on a project involving communications between a set of servers, so I set up a "base" server with the software I needed then cloned it multiple times. Of course, each cloned server had the same identifier, so they all received the same IP address from our DHCP server.
The answer to the question above solved the problem, but it left me wondering: How can I change the identifier assigned when Ubuntu is installed?
networking ubuntu dhcp
networking ubuntu dhcp
asked Dec 3 at 16:52
Kryten
21114
asked Dec 3 at 16:52
Kryten
21114
asked Dec 3 at 16:52
Kryten
21114
asked Dec 3 at 16:52
Kryten
21114
asked Dec 3 at 16:52
Kryten
21114
21114
add a comment |
add a comment |
1 Answer
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As I wrote in the thread you linked to, it generates the ID based on /etc/machine-id.
The default ClientIdentifier= mode in systemd-networkd is
duid, which means the DHCPv4 client ID is based on networkd's DHCPv6 DUID.
The default DUIDType= setting in networkd.conf is
vendor, which is described as:
If "DUIDType=vendor", then the DUID value will be generated using "43793" as
the vendor identifier (systemd) and hashed contents of machine-id(5). This is
the default if DUIDType= is not specified.
The machine-id is also used for generating other identifiers, such as IPv6 addresses, and so should be removed/recreated even if you don't use DHCP.
answered Dec 3 at 16:59
grawity
230k35484544
Thanks. I didn't read far enough to find your answer; I think I need more coffee this morning.
– Kryten
Dec 3 at 17:02
add a comment |
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1 Answer
1
active
oldest
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1 Answer
1
active
oldest
votes
active
oldest
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active
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up vote
0
down vote
As I wrote in the thread you linked to, it generates the ID based on /etc/machine-id.
The default ClientIdentifier= mode in systemd-networkd is
duid, which means the DHCPv4 client ID is based on networkd's DHCPv6 DUID.
The default DUIDType= setting in networkd.conf is
vendor, which is described as:
If "DUIDType=vendor", then the DUID value will be generated using "43793" as
the vendor identifier (systemd) and hashed contents of machine-id(5). This is
the default if DUIDType= is not specified.
The machine-id is also used for generating other identifiers, such as IPv6 addresses, and so should be removed/recreated even if you don't use DHCP.
answered Dec 3 at 16:59
grawity
230k35484544
Thanks. I didn't read far enough to find your answer; I think I need more coffee this morning.
– Kryten
Dec 3 at 17:02
add a comment |
up vote
0
down vote
As I wrote in the thread you linked to, it generates the ID based on /etc/machine-id.
The default ClientIdentifier= mode in systemd-networkd is
duid, which means the DHCPv4 client ID is based on networkd's DHCPv6 DUID.
The default DUIDType= setting in networkd.conf is
vendor, which is described as:
If "DUIDType=vendor", then the DUID value will be generated using "43793" as
the vendor identifier (systemd) and hashed contents of machine-id(5). This is
the default if DUIDType= is not specified.
The machine-id is also used for generating other identifiers, such as IPv6 addresses, and so should be removed/recreated even if you don't use DHCP.
answered Dec 3 at 16:59
grawity
230k35484544
Thanks. I didn't read far enough to find your answer; I think I need more coffee this morning.
– Kryten
Dec 3 at 17:02
add a comment |
up vote
0
down vote
up vote
0
down vote
As I wrote in the thread you linked to, it generates the ID based on /etc/machine-id.
The default ClientIdentifier= mode in systemd-networkd is
duid, which means the DHCPv4 client ID is based on networkd's DHCPv6 DUID.
The default DUIDType= setting in networkd.conf is
vendor, which is described as:
If "DUIDType=vendor", then the DUID value will be generated using "43793" as
the vendor identifier (systemd) and hashed contents of machine-id(5). This is
the default if DUIDType= is not specified.
The machine-id is also used for generating other identifiers, such as IPv6 addresses, and so should be removed/recreated even if you don't use DHCP.
answered Dec 3 at 16:59
grawity
230k35484544
As I wrote in the thread you linked to, it generates the ID based on /etc/machine-id.
The default ClientIdentifier= mode in systemd-networkd is
duid, which means the DHCPv4 client ID is based on networkd's DHCPv6 DUID.
The default DUIDType= setting in networkd.conf is
vendor, which is described as:
If "DUIDType=vendor", then the DUID value will be generated using "43793" as
the vendor identifier (systemd) and hashed contents of machine-id(5). This is
the default if DUIDType= is not specified.
The machine-id is also used for generating other identifiers, such as IPv6 addresses, and so should be removed/recreated even if you don't use DHCP.
answered Dec 3 at 16:59
grawity
230k35484544
answered Dec 3 at 16:59
grawity
230k35484544
answered Dec 3 at 16:59
grawity
230k35484544
answered Dec 3 at 16:59
grawity
230k35484544
230k35484544
Thanks. I didn't read far enough to find your answer; I think I need more coffee this morning.
– Kryten
Dec 3 at 17:02
add a comment |
Thanks. I didn't read far enough to find your answer; I think I need more coffee this morning.
– Kryten
Dec 3 at 17:02
Thanks. I didn't read far enough to find your answer; I think I need more coffee this morning.
– Kryten
Dec 3 at 17:02
Thanks. I didn't read far enough to find your answer; I think I need more coffee this morning.
– Kryten
Dec 3 at 17:02
add a comment |
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