CBS350 can't get IP from DHCP server

sunnywang · ‎05-02-2023

Hi everyone,

My network architecture is as below.
On Juniper SRX340: I create a DHCP server and VLAN 10 .
On Cisco switch: I create vlan10 and set all the interfaces to vlan10.
Question: When my notebook connects to the switch I can't get the IP.
I'm new to Juniper and Cisco. Is there any missing setting?

## SRX340
set interfaces ge-0/0/1 description CBS350_01
set interfaces ge-0/0/1 vlan-tagging
set interfaces ge-0/0/1 unit 0 vlan-id 10
set interfaces ge-0/0/1 unit 0 family inet address 172.11.1.11/24
set interfaces ge-0/0/2 description CBS350_02
set interfaces ge-0/0/2 vlan-tagging
set interfaces ge-0/0/2 unit 0 vlan-id 10
set interfaces ge-0/0/2 unit 0 family inet address 172.11.1.12/24

set security zones security-zone ZONE_TRUST host-inbound-traffic system-services dhcp
set security zones security-zone ZONE_TRUST interfaces ge-0/0/1.0
set security zones security-zone ZONE_TRUST interfaces ge-0/0/2.0


set routing-instances trust-vr system services dhcp-local-server group JDHCP-GROUP interface ge-0/0/1.0
set routing-instances trust-vr system services dhcp-local-server group JDHCP-GROUP interface ge-0/0/2.0
set routing-instances trust-vr access address-assignment pool JDHCPVR-POOL family inet network 172.11.1.0/24
set routing-instances trust-vr access address-assignment pool JDHCPVR-POOL family inet range DHCP-RANGE low 172.11.1.40
set routing-instances trust-vr access address-assignment pool JDHCPVR-POOL family inet range DHCP-RANGE high 172.11.1.250
set routing-instances trust-vr access address-assignment pool JDHCPVR-POOL family inet dhcp-attributes domain-name aaa.bbb
set routing-instances trust-vr access address-assignment pool JDHCPVR-POOL family inet dhcp-attributes name-server 8.8.8.8
set routing-instances trust-vr access address-assignment pool JDHCPVR-POOL family inet dhcp-attributes router 172.11.1.1
set routing-options static route 0.0.0.0/0 next-hop pp0.0

##CBS350_01
interface vlan 10
 name default_internet
 ip address 172.11.1.11 255.255.255.0

!
interface GigabitEthernet1
 description internal
 switchport access vlan 10
!
interface GigabitEthernet2
 description internal
 switchport access vlan 10

ip default-gateway 172.11.1.1

##CBS350_02
interface vlan 10
 name default_internet
 ip address 172.11.1.12 255.255.255.0

!
interface GigabitEthernet1
 description internal
 switchport access vlan 10
!
interface GigabitEthernet2
 description internal
 switchport access vlan 10

ip default-gateway 172.11.1.1

Richard Burts · ‎05-02-2023

I do not have a lot of expertise with Juniper but my understanding of the Juniper config is that it will be doing vlan tagging on both of the interfaces connecting to your Cisco switches. So the ethernet frames will have a vlan tag for vlan 10. But the switches configure their interfaces as access ports, which do not understand vlan tags. Either change the Juniper to remove the vlan tags or change the Cisco to make the interfaces into trunk ports.

HTH

Rick