I have M7i router for simulation.
What M7i is ?
M7i is the smallest router in the M-series family of Juniper.
M7i has 7G capacity and usually used for medium enterprises networks.
But many customers used it for bigger application such as internet gateway routers.
M7i memory can be upgrade until 2G.
But here, it only have 256Mb…. Uh… very small.
enugadi@M7i# run show version
Hostname: M7i
Model: m7i
JUNOS Base OS boot [7.6R3.6]
JUNOS Base OS Software Suite [7.6R3.6]
JUNOS Kernel Software Suite [7.6R3.6]
JUNOS Packet Forwarding Engine Support (M7i/M10i) [7.6R3.6]
JUNOS Routing Software Suite [7.6R3.6]
JUNOS Online Documentation [7.6R3.6]
JUNOS Crypto Software Suite [7.6R3.6]
[edit]
enugadi@M7i# run show chassis routing-engine
Routing Engine status:
Temperature 21 degrees C / 69 degrees F
CPU temperature 19 degrees C / 66 degrees F
DRAM 256 MB
Memory utilization 87 percent
CPU utilization:
User 0 percent
Background 0 percent
Kernel 2 percent
Interrupt 0 percent
Idle 97 percent
Model RE-5.0
Serial ID xxxxxxx
Start time 2007-10-31 03:10:55 UTC
Uptime 5 hours, 2 minutes, 29 seconds
Load averages: 1 minute 5 minute 15 minute
0.01 0.02 0.00 Here, it only have 256Mb…. Uh… very small. Usually it reach until 95-98%. In the first boot, it has something about 80% CPU processing.
enugadi@M7i# run show route summary
Autonomous system number: xxxx
Router ID: x.x.x.x
inet.0: 239007 destinations, 239007 routes (239007 active, 0 holddown, 0 hidden)
Direct: 3 routes, 3 active
Local: 3 routes, 3 active
BGP: 239000 routes, 239000 active
Aggregate: 1 routes, 1 active
__juniper_private1__.inet.0: 2 destinations, 2 routes (2 active, 0 holddown, 0 hidden)
Direct: 1 routes, 1 active
Local: 1 routes, 1 active
__juniper_private1__.inet6.0: 5 destinations, 5 routes (5 active, 0 holddown, 0 hidden)
Direct: 3 routes, 3 active
Local: 2 routes, 2 active 239000 is active routes installed in my M7i.
Full internet prefix 
Even M7i is the smallest one, it can handle full internet prefix with high stability.
M7i have builtin ethernet 2 port and tunnel service PIC.
Tunnel service PIC will generate interface for tunneling.
Each tunnel PIC can simultaneously support a number of different
tunnel types facilitating a wide range of applications:
• IP-IP Encapsulation: IP-IP enables the transport of IPv4 and IPv6
over disparate IP infrastructures that may be owned by a third
party or have disjointed capabilities or policies.
• Generic Routing Encapsulation: GRE is an alternative to IP-IP that
supports IPSec and non-IP protocols such as MPLS in addition
to IPv4 and IPv6 over any IP infrastructure. Juniper Networks
implementation of GRE complies with RFC 1701 and RFC 1702.
• PIM Sparse Mode Encapsulation: Supports PIM-SM encapsulation
and de-encapsulation on source designated routers (DR) and
rendezvous points (RPs).
• Logical Tunnels: Logical Tunnels create a virtual interface within
the router that supports the interconnection of VPNs and
communication between logical routers.
• Virtual Tunnels: Virtual Tunnels support Virtual Private LAN
Service (VPLS)
• Multicast Tunnels: Multicast Tunnels are used to create Multicast
Distribution Trees (MDT), which transport VPN multicast packets
across a RFC 2547bis Layer 3 VPN network.
