Juniper MX routers are universal routing platforms for enterprise edges, data center links and service provider networks. Because they all run Junos OS, the same skills apply from a compact 1U box to a large modular chassis.
This guide compares the MX204 and MX304 for edge routing. It also explains which MPC7E line cards and routing engines fit an existing MX240, MX480 or MX960, so you can expand without replacing the whole chassis.
What Juniper MX routers do
MX routers handle routing at the network edge and in the core. For example, an enterprise might use one for internet peering, while a carrier might run dozens for aggregation. Because every MX runs Junos OS, the same skills and configs carry across models.
The range also splits into compact and modular platforms. The MX204 and MX304 are compact, while the MX240, MX480 and MX960 take line cards and routing engines. As a result, you can either buy a new compact router or grow a chassis you already own.
Juniper MX routers compared: MX204 vs MX304
MX204
The MX204 is a 1U router with 400 Gbps of throughput. It has 4 rate-selectable QSFP28 ports for 100GbE, 40GbE or 4x10GbE, plus 8 10GbE SFP+ ports. In addition, it has a built-in routing engine, two AC or DC power supplies and front-to-back airflow.
When you order the MX204, the base hardware model is the MX204-HW-BASE. It takes either the JPSU-650W-AC-AO AC supply or the JPSU-650W-DC-AFO DC supply, so check your power feed before you order.
MX304
In contrast, the MX304 is a 2U router with 4.8 Tbps of system capacity. It supports up to 12x400GbE or 48x100GbE ports through up to three LMIC line cards. Each MX304-LMIC16-BASE card has 16 ports and 1.6 Tbps of capacity, and it runs as 16x100GbE, 4x400GbE or a mix.
Also, the MX304 comes as a base model with one routing engine or as the MX304-PREM. So the premium bundle adds a second routing engine for redundancy, along with two power supplies and three fan trays.
Which one fits?
Choose the MX204 when 400 Gbps covers your traffic and you want a compact edge router. However, if you need 400GbE ports, more capacity or routing engine redundancy, the MX304 is the better fit. Since you can add LMIC cards later, the MX304 also leaves room to grow.
Line cards for MX240, MX480 and MX960
If you already run an MX240, MX480 or MX960, line cards are often the cheapest way to add ports. The MPC7E-10G has 40 10GbE SFP+ ports that also run at 1G, with up to 400 Gbps of line-rate throughput. Meanwhile, the MPC7E-MRATE has 12 QSFP+ ports for 40GbE or 4x10GbE, and 4 of them run 100GbE with QSFP28 optics.
Before you install it, the MPC7E-10G needs the chassis to run in enhanced-ip or enhanced-ethernet mode. It also needs SCBE2 or SCBE3 switch control boards on the MX240, MX480 and MX960, plus an adapter card on the MX2000. So check the same points for the MPC7E-MRATE before you order.
Routing engines for Juniper MX routers
In short, the routing engine is the brain of the chassis. The RE-S-X6-128G fits the MX240, MX480 and MX960, with a 2.0 GHz 6-core CPU, 128 GB of DRAM and two 200 GB SSDs. Similarly, it works with SCBE2 or SCBE3 switch control boards, just as the MPC7E-10G does.
So before you upgrade, check which switch control boards your chassis has. Also, if you run two routing engines, order a matching pair so both sides behave the same way.
Common mistakes when buying MX hardware
The most common mistake is buying a line card your chassis cannot run. For instance, an older chassis may still have switch control boards that do not meet the MPC7E requirements. Another mistake is forgetting software licensing, since some MX features need a license on top of the hardware.
Also, match power to your site. An MX204 can run on AC or DC, so confirm the feed type before you order spare supplies.
Juniper MX routers part numbers we supply
Silverback supplies every part below in new or used condition. So send us the part number, and get pricing and lead time within one business day.
| Part number | Product | Notes |
|---|---|---|
| MX204 | MX204 universal routing platform | 1U, 400 Gbps, 4x QSFP28 plus 8x 10GbE SFP+ |
| MX204-HW-BASE | MX204 base hardware model | AC or DC power supplies, built-in routing engine |
| MX304 | MX304 universal routing platform | 2U, 4.8 Tbps, up to three LMIC line cards |
| MX304-PREM | MX304 premium chassis bundle | Two routing engines, two PSUs, three fan trays |
| MX304-LMIC16-BASE | MX304 LMIC16 line card | 16 ports, 1.6 Tbps, 100GbE or 400GbE, MACsec |
| MPC7E-10G | MPC7E 40-port 10GbE line card | MX240, MX480, MX960, MX2000; up to 400 Gbps |
| MPC7E-MRATE | MPC7E multi-rate line card | 12x QSFP+, 4 run 100GbE; up to 480 Gbps |
| RE-S-X6-128G | RE-S-X6-128G routing engine | MX240, MX480, MX960; 6-core CPU, 128 GB DRAM |
New vs used Juniper MX routers
Used MX hardware is popular, because routers and line cards hold up well over time. For example, a used MPC7E-10G can add 40 10G ports to an MX480 for far less than a new card. Still, new hardware makes sense for a fresh build that needs a long support runway.
Silverback supplies new and used routers, line cards and routing engines, tested before they ship. So ask for new or used condition, and read refurbished vs new enterprise hardware to compare.
Buyback and why buy Juniper MX routers from Silverback
When you retire routing gear, Silverback buys it back and offers certified data destruction under R2v3, ISO 14001 and ISO 45001. See how IT buyback value works for details.
Silverback is a trusted supplier of Juniper hardware and also a certified HPE Business Partner. Browse the full Juniper product range, compare QFX data center switches, or pair your router with an SRX firewall.
Of course, full specs live on juniper.net. Meanwhile, you can browse our inventory or request pricing for any part above.
Frequently Asked Questions
What is the difference between the MX204 and MX304?
The MX204 is a 1U router with 400 Gbps of throughput and built-in ports. The MX304 is a 2U router with 4.8 Tbps of capacity, up to three LMIC line cards and one or two routing engines.
Will an MPC7E-10G work in my MX480?
Yes, as long as the chassis runs in enhanced-ip or enhanced-ethernet mode and has SCBE2 or SCBE3 switch control boards.
What is the MX304-PREM?
It is the premium MX304 bundle with two routing engines, two power supplies and three fan trays. In contrast, the base model has one routing engine.
Which routing engine fits the MX960?
The RE-S-X6-128G fits the MX240, MX480 and MX960, and it works with SCBE2 or SCBE3 switch control boards.
Do you sell used MX routers?
Yes. Silverback supplies new and used MX routers, line cards and routing engines, tested before they ship. Ask for new or used condition when you request a quote.
Get a quote for Juniper MX routers
Whether you need a single MX204 or a set of MPC7E-10G cards for an MX960, Silverback can help. Send us your part list, and we will reply with pricing and lead time within one business day.
Then call (888) 391-5211 or get a free quote online. Ask for new or used condition, and we will check each part against your chassis.
