Juniper · Data-centre SRX
Juniper SRX4120
The Juniper SRX4120 is a rackmount firewall that runs Junos OS. Juniper publishes a firewall throughput of 39 Gbps for it. It has 8 x 1/2.5/5/10GbE copper, 8 x 1GbE/10GbE SFP+, 4 x 1/10/25GbE SFP28, 2 x 40GbE/100GbE QSFP28, 2 x 1GbE SFP high-availability ports.
- Firewall throughput
- 39 Gbps
- Threat protection
- Not published
- IPsec VPN
- 36 Gbps (1400-byte)
- Form
- Rackmount
Who it suits
As a rackmount unit it suits a head office, campus or data centre with a server rack.
Juniper SRX4120 specifications
| Performance | |
|---|---|
| Firewall throughput | 39 Gbps |
| Firewall throughput (IMIX) | 28 Gbps |
| IPsec VPN throughput | 36 Gbps (1400-byte) / 18 Gbps (IMIX) |
| Hardware | |
| Form factor | 1U |
| Ports | 8 x 1/2.5/5/10GbE copper, 8 x 1GbE/10GbE SFP+, 4 x 1/10/25GbE SFP28, 2 x 40GbE/100GbE QSFP28, 2 x 1GbE SFP high-availability ports |
| Storage | 2 x 120 GB SSD |
| Power supply | 2 hot-swappable supplies, redundant (1+1): 450 W AC or 650 W DC |
| Power consumption | 229 W maximum (AC) |
| Dimensions | 43.89 x 4.42 x 46.23 cm (W x H x D) |
| Weight | 7.76 kg (8.67 kg with two power supplies) |
Specifications from Juniper's published data, checked October 2026. See Juniper's firewall pages. Throughput figures are each manufacturer's own published numbers. Manufacturers test in different ways, so compare across brands with care. Confirm details before ordering.
What we do with it
- Supply
Firewall supply and installation
The right-sized firewall from any of the five brands, with its licence, installed and configured at your site.
- Audit
Firewall configuration and audit
A review of your rules, firmware, admin access and VPNs, with the weak points fixed and written down.
- Renewal
Firewall licence renewal
Renewals for FortiGuard, Sophos, Palo Alto Networks, SonicWall and Juniper subscriptions, quoted from your serial number.
- Migrate
Firewall migration
Move from an old firewall to a new one, same brand or another, with the rules and VPNs carried over.
Questions about the SRX4120
What ports does the SRX4120 have?
8 x 1/2.5/5/10GbE copper, 8 x 1GbE/10GbE SFP+, 4 x 1/10/25GbE SFP28, 2 x 40GbE/100GbE QSFP28, 2 x 1GbE SFP high-availability ports.
Does the SRX4120 need a licence?
The hardware works as a basic firewall on its own. Protection features such as intrusion prevention, web filtering and anti-malware need an active Juniper subscription, and so do firmware updates and support. We quote the firewall with the licence term you choose.
Do you supply the SRX4120 with installation?
Yes. We supply it with its licence registered, install and configure it at your site, and hand over the logins and documentation. Ask for a quote on this page.
Similar Juniper models
- Rackmount
Juniper SRX2300
Firewall 39 Gbps, threat protection 12 Gbps (NGFW)
- Rackmount
Juniper SRX4100
Firewall 40 Gbps, threat protection 13.9 Gbps (IPS)
- Rackmount
Juniper SRX4600
Firewall 400 Gbps, threat protection 21 Gbps (NGFW)
- Rackmount
Juniper SRX1600
Firewall 24 Gbps, threat protection 4.5 Gbps (NGFW)
Closest models from other brands
Throughput figures are each manufacturer's own published numbers. Manufacturers test in different ways, so compare across brands with care.
- Rackmount
Fortinet FortiGate 400F
threat protection 9 Gbps
- Rackmount
Sophos XGS 3300
Firewall 58 Gbps, threat protection 10 Gbps
- Rackmount
Palo Alto Networks PA-3420
Firewall 19 Gbps, threat protection 10 Gbps
- Rackmount
SonicWall NSa 4700
Firewall 18 Gbps, threat protection 9.5 Gbps