SRX

Hi Everyone,

    I have a workstation that is having issues connecting to the internet via an SRX device. From the SRX device I am able to reach the internet however, when I try to reach the internet from the workstation station I am unable too. Below is ping results from the SRX device. I also put a small diagram so you can see the layout and the configs on the SRX device. Please advise on what could be the issue?

xxxx@Juniper1> show configuration | display set
set system name-server 208.67.222.222
set system name-server 208.67.220.220
set system services ssh
set system services telnet
set system services xnm-clear-text
set system services web-management http interface vlan.0
set system services web-management https system-generated-certificate
set system services web-management https interface vlan.0
set system services dhcp router 10.1.1.1
set system services dhcp pool 10.1.1.0/24 address-range low 10.1.1.2
set system services dhcp pool 10.1.1.0/24 address-range high 10.1.1.254
set system syslog archive size 100k
set system syslog archive files 3
set system syslog user * any emergency
set system syslog file messages any critical
set system syslog file messages authorization info
set system syslog file interactive-commands interactive-commands error
set system max-configurations-on-flash 5
set system max-configuration-rollbacks 5
set system license autoupdate url https://ae1.juniper.net/junos/key_retrieval
set interfaces fe-0/0/0 unit 0 family inet dhcp
set interfaces fe-0/0/1 unit 0 family ethernet-switching vlan members vlan-trust
set interfaces fe-0/0/2 unit 0 family ethernet-switching vlan members vlan-trust
set interfaces fe-0/0/3 unit 0 family ethernet-switching vlan members vlan-trust
set interfaces fe-0/0/4 unit 0 family ethernet-switching vlan members vlan-trust
set interfaces fe-0/0/5 unit 0 family ethernet-switching vlan members vlan-trust
set interfaces fe-0/0/6 unit 0 family ethernet-switching vlan members vlan-trust
set interfaces fe-0/0/7 unit 0 family ethernet-switching vlan members vlan-trust
set interfaces vlan unit 0 family inet address 10.1.1.1/24
set protocols stp
set security screen ids-option untrust-screen icmp ping-death
set security screen ids-option untrust-screen ip source-route-option
set security screen ids-option untrust-screen ip tear-drop
set security screen ids-option untrust-screen tcp syn-flood alarm-threshold 1024
set security screen ids-option untrust-screen tcp syn-flood attack-threshold 200
set security screen ids-option untrust-screen tcp syn-flood source-threshold 1024
set security screen ids-option untrust-screen tcp syn-flood destination-threshold 2048
set security screen ids-option untrust-screen tcp syn-flood timeout 20
set security screen ids-option untrust-screen tcp land
set security nat source rule-set trust-to-untrust from zone trust
set security nat source rule-set trust-to-untrust to zone untrust
set security nat source rule-set trust-to-untrust rule source-nat-rule match source-address 0.0.0.0/0
set security nat source rule-set trust-to-untrust rule source-nat-rule then source-nat interface
set security policies from-zone trust to-zone untrust policy trust-to-untrust match source-address any
set security policies from-zone trust to-zone untrust policy trust-to-untrust match destination-address any
set security policies from-zone trust to-zone untrust policy trust-to-untrust match application any
set security policies from-zone trust to-zone untrust policy trust-to-untrust then permit
set security zones security-zone trust host-inbound-traffic system-services all
set security zones security-zone trust host-inbound-traffic protocols all
set security zones security-zone trust interfaces vlan.0
set security zones security-zone trust interfaces fe-0/0/7.0
set security zones security-zone untrust screen untrust-screen
set security zones security-zone untrust interfaces fe-0/0/0.0 host-inbound-traffic system-services dhcp
set security zones security-zone untrust interfaces fe-0/0/0.0 host-inbound-traffic system-services tftp
set vlans vlan-trust vlan-id 3
set vlans vlan-trust l3-interface vlan.0

xxxx@Juniper1> ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8): 56 data bytes
64 bytes from 8.8.8.8: icmp_seq=0 ttl=250 time=40.343 ms
64 bytes from 8.8.8.8: icmp_seq=1 ttl=250 time=36.330 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=250 time=36.137 ms
64 bytes from 8.8.8.8: icmp_seq=3 ttl=250 time=35.973 ms
64 bytes from 8.8.8.8: icmp_seq=4 ttl=250 time=37.613 ms
^C
--- 8.8.8.8 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max/stddev = 35.973/37.279/40.343/1.638 ms

victor@Juniper1>

Thank you

Victor

Your workstation does not have DNS information, under DHCP hierarchy configure DNS information or configure static entry in your work station

The workstation received the DNS server from the SRX and I even statically configured a DNS server on the workstation and it still not reach the internet.

A quick glance does not show anything wrong. 

If you execute the operational mode command > show security flow session and match on the IP prefix of the PC do you see a session established for the flow? You should see outbound packets at least. 

When I match for the host workstation I don't see anything. I am trying to ping DNS 8.8.8.8 when trying performing the match. See below:

user@Juniper1> show security flow session | match 10.1.1.2

Dear 

I don't see any need to put the below line in the config 

set security zones security-zone trust interfaces fe-0/0/7.0

 as interface is ethernet-switching and member for vlan-trust (set interfaces fe-0/0/7 unit 0 family ethernet-switching vlan members vlan-trust) , so only l3-interface vlan.0 should be member of the zone which is already in your config, 

to understand what happen to your ping packet , the best way is to enable traceoption under security flow

[edit security flow traceoptions]
SRX# show
file reachability-internet;
flag basic-datapath;
packet-filter filter-1 {
protocol icmp;
destination-prefix 8.8.8.8/32;

source-prefix 10.1.1.2/32

}

Regards

Hi,

under "set system services dhcp pool" you must "propagate-settings vlan.0". interface for propagate dhcp.

also try under "security zones security-zone trust interfaces vlan.0" put "host-inbound-traffic protocols all"

for test make ping from srx vlan interface

ping 8.8.8.8 interface vlan.0

Its working now. I am able to reach the internet not sure what was going on. I checked the flow sessions again and saw various sessions being established to the internet. Thank you all for your help.

Happy to know that 🙂 , you are welcome!