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set access address-assignment pool wifi family inet network 172.16.8.0/21set access address-assignment pool wifi family inet range wifi low 172.16.8.120set access address-assignment pool wifi family inet range wifi high 172.16.15.254set access address-assignment pool wifi family inet dhcp-attributes maximum-lease-time 108000set access address-assignment pool wifi family inet dhcp-attributes name-server 126.96.36.199set access address-assignment pool wifi family inet dhcp-attributes name-server 188.8.131.52set access address-assignment pool wifi family inet dhcp-attributes name-server 184.108.40.206set access address-assignment pool wifi family inet dhcp-attributes router 172.16.8.1
You can confirm what the current setting is with this status commandshow system services dhcp statisticsI think without setting any it should be 2 hours.Do you have dhcp as an allowed service for the zone of the gateway interface?
This command is showing not valid on ex4650 and if this is by default two hours still ips are changing in few minutes after disconnect and connecting again.admin@jklucoreswitch> show system services dhcp statisticserror: command is not valid on the ex4650-48y-8c
Sorry, I missed this was EX and not SRX.Do you have the interface assigned in the system area?set system services dhcp-local-server group-name interface interface-namehttps://www.juniper.net/documentation/en_US/junos/topics/topic-map/dhcp-for-switching-devices.html#id-configuring-a-switch-as-a-dhcp-server-cli-procedure
i have assigned the interface on irb and assigned ip addresses to irb interfaces and made them l3 interface. is there any issue with server identifier command. i have not assigned the server identifier command.set system services dhcp-local-server group IT interface irb.101set system services dhcp-local-server group admin interface irb.102set system services dhcp-local-server group faculty interface irb.105set system services dhcp-local-server group event interface irb.108set system services dhcp-local-server group residence interface irb.110set system services dhcp-local-server group wifi interface irb.104set system services dhcp-local-server group hostel interface irb.109set interfaces irb unit 100 family inet address 172.16.1.2/25set interfaces irb unit 101 family inet address 172.16.3.1/24set interfaces irb unit 102 family inet address 172.16.2.1/24set interfaces irb unit 103 family inet address 172.16.4.1/22set interfaces irb unit 104 family inet address 172.16.8.1/21set interfaces irb unit 105 family inet address 172.16.25.1/24set interfaces irb unit 106 family inet address 172.16.26.1/24set interfaces irb unit 108 family inet address 172.16.32.1/20set interfaces irb unit 109 family inet address 172.16.16.1/21set interfaces irb unit 110 family inet address 172.16.48.1/21set protocols router-advertisement interface irb.0set vlans IT l3-interface irb.101set vlans LAB l3-interface irb.103set vlans admin l3-interface irb.102set vlans cctv l3-interface irb.106set vlans event l3-interface irb.108set vlans faculty l3-interface irb.105set vlans fire l3-interface irb.100set vlans hostel l3-interface irb.109set vlans residence l3-interface irb.110set vlans wifi l3-interface irb.104
The configuration looks complete. Do you have any firewall filters applied on the switch? If a protection filter is applied to the loopback or any fixed interface it might be interfering with the traffic.If not, we need to see what the status is of the EX dhcp systemConfirm that all the settings configured are being activatedshow system services dhcp poolAlso confirm that DHCP snooping, ARP inspection or Mac limiting are not enabled for port security.If none of this applies, we need to turn on logging, called trace options in Junos. This specifies a file and we can see all the transactions and errors and see why the leases are being changed so frequently.
Configure debug logging and commit
set system processes dhcp-service traceoptions file dhcpLog
set system processes dhcp-service traceoptions flag all
show logs after commit
show log dhcpLog
I have not applied any firewall filter on the switch. but i have enabled arp inspection on two VLANs. Mac limiting is not there. i can remove them if required.admin@jklucoreswitch> show configuration |display set |match inspectionset vlans hostel forwarding-options dhcp-security arp-inspectionset vlans wifi forwarding-options dhcp-security arp-inspection
Configure debug logging and commitset system processes dhcp-service traceoptions file dhcpLog set system processes dhcp-service traceoptions flag allshow logs after commitshow log dhcpLog