Supported Platforms
Related Documentation
- QFabric System, QFX Series standalone switches
- Configuring the Unified Forwarding Table
Understanding the Unified Forwarding Table
Using the Unified Forwarding Table to Optimize Address Storage
On the QFX5100 switch, you can control the allocation of forwarding table memory available to store the following:
- MAC addresses.
- Layer 3 host entries.
- Longest prefix match (LPM) table entries.
Note: Starting with Junos OS 13.2X51-D15, you can allocate more memory to store prefixes in the range /65 to /127 range.
This feature gives you the flexibility to configure your QFX5100 to match the needs of your particular network environment.
MAC Address and Host Address Memory Allocation
There are several profiles that allocate memory differently for MAC addresses and host addresses. You configure the mix that best meets your needs by choosing the appropriate profile. Table 1 lists the profiles you can choose and the associated maximum values for the MAC address and host table entries.
Table 1: Unified Forwarding Table Profiles
| Profile Name | MAC Table | Host Table (unicast and multicast addresses) | |||||
|---|---|---|---|---|---|---|---|
| MAC Addresses | IPv4 unicast | IPv6 unicast | IPv4 (*, G) | IPv4 (S, G) | IPv6 (*, G) | IPv6 (S, G) | |
l2-profile-one | 288K | 16K | 8K | 8K | 8K | 4K | 4K |
l2-profile-two | 224K | 80K | 40K | 40K | 40K | 20K | 20K |
l2-profile-three (default) | 160K | 144K | 72K | 72K | 72K | 36K | 36K |
l3-profile | 96K | 208K | 104K | 104K | 104K | 52K | 52K |
lpm-profile | 32K | 16K | 8K | 8K | 8K | 4K | 4K |
Note that all entries in the host table share the same memory space. If the host table stores the maximum number of entries for any given type, the entire shared table is full and is unable to accommodate any entries of any other type. As you can see, different entry types occupy different amounts of memory. For example, an IPv6 unicast address occupies twice as much memory as an IPv4 unicast address, and an IPv6 multicast address occupies four times as much memory as an IPv4 unicast address. Table 2 lists various valid combinations that the host table can store if you use the l2-profile-one profile. Each row in the table represents a case in which the host table is full and cannot accommodate any more entries. .
Table 2: Example Host Table Combinations Using l2-profile-one
| IPv4 unicast | IPv6 unicast | IPv4 multicast (*, G) | IPv4 multicast (S, G) | IPv6 multicast (*, G) | IPv6 multicast (S, G) |
|---|---|---|---|---|---|
16K | 0 | 0 | 0 | 0 | 0 |
12K | 2K | 0 | 0 | 0 | 0 |
12K | 0 | 2K | 2K | 0 | 0 |
8K | 4K | 0 | 0 | 0 | 0 |
4K | 2K | 2K | 2K | 0 | 0 |
0 | 4K | 0 | 0 | 1K | 1K |
LPM Table Memory Allocation
You configure the memory allocation for LPM table entries differently depending on which version of Junos OS you use. To learn how to configure memory allocation for LPM table entries see Configuring the Unified Forwarding Table.
Related Documentation
- QFabric System, QFX Series standalone switches
- Configuring the Unified Forwarding Table
Published: 2014-06-30
Supported Platforms
Related Documentation
- QFabric System, QFX Series standalone switches
- Configuring the Unified Forwarding Table
