RoutingEXEC

show route summary

Displays a summary of the routing table, including route counts by protocol and table statistics.

Overview

The 'show route summary' command is a fundamental diagnostic tool on Cisco IOS-XR routers. It provides a concise overview of the routing table's composition, including the number of routes learned from each routing protocol (connected, static, OSPF, BGP, etc.), backup paths, deleted routes, and memory consumption. This command is essential for network engineers to quickly assess the scale of the routing table, verify redistribution, and monitor for anomalies such as route leaks or flapping. On IOS-XR, the command supports filtering by VRF and address family (IPv4/IPv6, unicast/multicast), making it versatile for complex network environments. It fits into troubleshooting workflows as a first step: checking route counts can reveal missing routes (e.g., if BGP routes are not being installed) or unexpected routes (e.g., from misconfigured redistribution). The output also helps in capacity planning by showing memory usage. Unlike Cisco IOS, IOS-XR separates the routing table into multiple tables per VRF and address family, so the command's output is scoped accordingly. Understanding this command is crucial for CCNP and CCIE candidates, as it tests knowledge of routing table structure and protocol behavior.

Syntax·EXEC

show route summary [vrf vrf-name] [ipv4 | ipv6] [unicast | multicast]

When to Use This Command

Quickly check the total number of routes in the routing table to assess network scale.
Verify redistribution by comparing route counts per protocol (e.g., OSPF, BGP, connected).
Monitor memory usage by checking the number of routes and paths.
Troubleshoot route leaks or missing routes by comparing expected vs actual counts.

Parameters

Parameter	Syntax	Required	Description
vrf vrf-name	vrf vrf-name	Optional	Specifies the VRF for which to display the route summary. If omitted, the default VRF is used.
ipv4 \| ipv6	ipv4 \| ipv6	Optional	Filters the output to show only IPv4 or IPv6 routes. If omitted, both address families are shown (but typically IPv4 is default).
unicast \| multicast	unicast \| multicast	Optional	Filters the output to show only unicast or multicast routes. If omitted, unicast is assumed.

Command Examples

Basic route summary for IPv4 unicast

show route summary

Route Source    Routes    Backup    Deleted    Memory (bytes)
connected       12        0         0          1536
static          2         0         0          256
application     0         0         0          0
ospf 100        45        5         0          6400
bgp 65000       120       10        0          19200
local           8         0         0          1024
Total           187       15        0          28416

Table ID: 0xe0000000 (default)
Number of prefixes: 187
Number of paths: 202
Maximum path limit: 32
Total network memory: 28416 bytes

The output shows route counts per protocol: connected (12), static (2), OSPF (45), BGP (120), local (8). Backup paths indicate ECMP or FRR. Total prefixes: 187, total paths: 202. Memory usage: 28416 bytes.

Route summary for a specific VRF

show route summary vrf CUSTOMER-A

Route Source    Routes    Backup    Deleted    Memory (bytes)
connected       5         0         0          640
static          1         0         0          128
bgp 65000       80        5         0          12800
local           3         0         0          384
Total           89        5         0          13952

Table ID: 0xe0000001 (CUSTOMER-A)
Number of prefixes: 89
Number of paths: 94
Maximum path limit: 32
Total network memory: 13952 bytes

For VRF CUSTOMER-A, routes are limited to that VRF. BGP has 80 routes with 5 backup paths. Total prefixes: 89, paths: 94. Memory usage is lower due to fewer routes.

Understanding the Output

The 'show route summary' command provides a high-level view of the routing table. The 'Route Source' column lists each routing protocol (connected, static, OSPF, BGP, etc.) and the number of routes learned from each. The 'Backup' column shows routes that have backup paths (e.g., for fast convergence or ECMP). The 'Deleted' column indicates routes pending deletion. The 'Memory (bytes)' column gives the memory consumption per protocol. The summary lines at the bottom show total prefixes, total paths (including backups), maximum path limit (typically 32), and total network memory. A healthy routing table should have no deleted routes and memory usage proportional to the number of routes. A sudden increase in deleted routes may indicate instability. High backup counts could indicate ECMP or FRR configurations. Comparing totals over time helps detect route leaks or flapping.

Configuration Scenarios

Verifying BGP route installation

A network engineer has configured BGP peering and wants to confirm that BGP routes are being installed in the routing table.

Topology

Router A (AS 65000) --- eBGP --- Router B (AS 65001)

Steps

1.Configure BGP on Router A with neighbor 192.0.2.2 remote-as 65001.
2.Check BGP summary with 'show bgp summary' to ensure the session is established.
3.Use 'show route summary' to see if BGP routes appear in the route source list.

Configuration

! Router A configuration
router bgp 65000
 neighbor 192.0.2.2 remote-as 65001
 address-family ipv4 unicast
  network 10.0.0.0/24
  neighbor 192.0.2.2 activate

Verify: After configuration, run 'show route summary' and look for 'bgp 65000' with a non-zero route count. If routes are missing, check BGP table with 'show bgp'.

Watch out: Ensure that the network statement matches exactly; otherwise, BGP may not advertise the route.

Troubleshooting with This Command

When troubleshooting routing issues on Cisco IOS-XR, 'show route summary' is a valuable starting point. For example, if a remote network is unreachable, first check the route summary to see if the expected protocol (e.g., OSPF or BGP) has any routes. A zero count for a protocol that should have routes indicates a problem with that protocol (e.g., neighbor down, redistribution not working). If the count is non-zero but the specific route is missing, proceed to 'show route' for that prefix. Another scenario: if the routing table is unexpectedly large, the summary can reveal which protocol is injecting too many routes (e.g., a misconfigured redistribution). The 'Backup' column can indicate ECMP or FRR; if backup paths are missing when expected, check for load-balancing or fast-reroute configuration. The 'Deleted' column should normally be zero; non-zero values suggest route flapping or pending removal due to policy changes. Memory usage can help identify memory leaks: if memory grows without a corresponding increase in routes, investigate further. On IOS-XR, you can also use 'show route summary vrf all' to check all VRFs at once. Remember that the command output is per-table; in a VRF-lite environment, each VRF has its own table. Always specify the VRF if troubleshooting a specific customer.

CCNA Exam Tips

Remember that 'show route summary' is a quick way to verify route redistribution and protocol operation.

On IOS-XR, the command supports VRF and address family filters; know how to specify them.

The 'Backup' column is important for understanding fast convergence features like FRR.

Common Mistakes

Confusing 'Backup' with 'Deleted' routes; backup paths are active alternatives, not stale.

Forgetting to specify VRF when troubleshooting multi-VRF environments, leading to incomplete data.

Misinterpreting memory usage as per-route instead of per-protocol; memory is cumulative per source.

Platform Notes

On Cisco IOS-XR, the 'show route summary' command differs from classic IOS in several ways. IOS-XR uses a modular architecture with separate routing tables per VRF and address family, so the command output is scoped to the current context (default VRF, IPv4 unicast unless specified). In classic IOS, 'show ip route summary' provides similar information but without the VRF and address family granularity. IOS-XR also includes a 'Backup' column, which is not present in classic IOS; this reflects the support for backup paths (e.g., for FRR). The memory usage column is also unique to IOS-XR, aiding in capacity planning. Equivalent commands on other platforms: Juniper's 'show route summary' is similar but with different formatting; Arista's 'show ip route summary' is closer to classic IOS. Version differences: In IOS-XR 6.x and later, the command supports 'all' keyword for VRFs. Always check the specific version documentation for any changes.

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