This article provides information on how to configure the DHCP on multiple VLANs in a SRX.
- Multiple address pools can be configured for a DHCP server. A different IP from separate address pools can be allocated to VLANs.
- DHCP maintains the state information for all the configured pools.
- Clients are assigned addresses from pools with subnets that match the interface on which the DHCPDISCOVER packet is received.
For version before 12.1 (DHCPD):
system {
host-name DHCP_VLAN;
root-authentication {
encrypted-password "$ABC123"; ## SECRET-DATA
}
services {
dhcp {
pool 192.168.15.0/24 {
address-range low 192.168.15.100 high 192.168.15.254;
router {
192.168.15.1;
}
propagate-settings vlan.300;
}
pool 192.168.16.0/24 {
address-range low 192.168.16.100 high 192.168.16.254;
router {
192.168.16.1;
}
propagate-settings vlan.100;
}
}
}
}
interfaces {
ge-2/0/0 {
unit 0 {
family ethernet-switching {
port-mode access;
vlan {
members test;
}
}
}
}
ge-2/0/1 {
unit 0 {
family ethernet-switching {
port-mode access;
vlan {
members test2;
}
}
}
}
}
vlan {
unit 100 {
family inet {
address 192.168.16.1/24;
}
}
unit 300 {
family inet {
address 192.168.15.1/24;
}
}
}
security {
zones {
security-zone trust {
interfaces {
vlan.300 {
host-inbound-traffic {
system-services {
dhcp;
}
protocols {
all;
}
}
}
vlan.100 {
host-inbound-traffic {
system-services {
dhcp;
}
protocols {
all;
}
}
}
}
}
}
}
vlans {
test {
vlan-id 300;
interface {
ge-2/0/0.0;
}
l3-interface vlan.300;
}
test2 {
vlan-id 100;
interface {
ge-2/0/1.0;
}
l3-interface vlan.100;
}
}
SRX-650
VERSION: 10.4R3.4
root@DHCP_VLAN# run show system services dhcp statistics
Sep 22 20:38:57
Packets dropped:
Total 0
Messages received:
BOOTREQUEST 0
DHCPDECLINE 0
DHCPDISCOVER 4
DHCPINFORM 7
DHCPRELEASE 0
DHCPREQUEST 5
Messages sent:
BOOTREPLY 0
DHCPOFFER 4
DHCPACK 12
DHCPNAK 0
[edit]
root@DHCP_VLAN# run show route
Sep 22 20:39:02
inet.0: 4 destinations, 4 routes (4 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
192.168.15.0/24 *[Direct/0] 00:02:43
> via vlan.300
192.168.15.1/32 *[Local/0] 01:44:13
Local via vlan.300
192.168.16.0/24 *[Direct/0] 00:05:07
> via vlan.100
192.168.16.1/32 *[Local/0] 00:16:45
Local via vlan.100
For version after 12.1, user may opt for using JDHCPD:
system {
host-name DHCP_VLAN;
root-authentication {
encrypted-password "$ABC123"; ## SECRET-DATA
}
services {
dhcp-local-server {
group test {
interface vlan.100;
interface vlan.300;
}
}
}
}
interfaces {
ge-2/0/0 {
unit 0 {
family ethernet-switching {
port-mode access;
vlan {
members test;
}
}
}
}
ge-2/0/1 {
unit 0 {
family ethernet-switching {
port-mode access;
vlan {
members test2;
}
}
}
}
}
vlan {
unit 100 {
family inet {
address 192.168.16.1/24;
}
}
unit 300 {
family inet {
address 192.168.15.1/24;
}
}
}
security {
zones {
security-zone trust {
interfaces {
vlan.300 {
host-inbound-traffic {
system-services {
dhcp;
}
protocols {
all;
}
}
}
vlan.100 {
host-inbound-traffic {
system-services {
dhcp;
}
protocols {
all;
}
}
}
}
}
}
}
access {
address-assignment {
pool p1 {
family inet {
network 192.168.15.0/24;
range r1 {
low 192.168.15.100;
high 192.168.15.254;
}
}
}
pool p2 {
family inet {
network 192.168.16.0/24;
range r2 {
low 192.168.16.100;
high 192.168.16.254;
}
}
}
}
}
vlans {
test {
vlan-id 300;
interface {
ge-2/0/0.0;
}
l3-interface vlan.300;
}
test2 {
vlan-id 100;
interface {
ge-2/0/1.0;
}
l3-interface vlan.100;
}
}
lab@SRX# run show dhcp statistics interface vlan.100
Packets dropped:
Total 0
Messages received:
BOOTREQUEST 2
DHCPDECLINE 0
DHCPDISCOVER 1
DHCPINFORM 0
DHCPRELEASE 0
DHCPREQUEST 1
Messages sent:
BOOTREPLY 2
DHCPOFFER 1
DHCPACK 1
DHCPNAK 0
DHCPFORCERENEW 0
lab@SRX# run show dhcp statistics interface vlan.300
Packets dropped:
Total 0
Messages received:
BOOTREQUEST 2
DHCPDECLINE 0
DHCPDISCOVER 1
DHCPINFORM 0
DHCPRELEASE 0
DHCPREQUEST 1
Messages sent:
BOOTREPLY 2
DHCPOFFER 1
DHCPACK 1
DHCPNAK 0
DHCPFORCERENEW 0
lab@SRX# run show interfaces terse vlan
Interface Admin Link Proto Local Remote
vlan up up
vlan.100 up up inet 192.168.16.1/24
vlan.300 up up inet 192.168.15.1/24
lab@SRX# run show dhcp server binding
IP address Session Id Hardware address Expires State Interface
192.168.16.100 3 00:24:dc:d9:7d:4f 82992 BOUND vlan.100
192.168.15.100 4 00:24:dc:d9:5d:41 82993 BOUND vlan.300