Using the BGP Updates Table

BGP Updates shows all of the updates for all of the prefixes your account is currently monitoring.

To view the BGP Updates table, from the navigation menu, select Routing > BGP Updates. You can also use the path visualization view to access the BGP Updates Table. Click "View all Updates" located on the top right corner of the timeline. You can also click on monitor and AS nodes in the path visualization view and click the BGP update table link from the information modal that pops up.

When you go to the BGP Updates table from the navigation menu, the table automatically displays BGP update activity for the past 1 day. When you use the path visualization timeline to view the BGP Update Table, the update activity shown uses the same time range that was selected in the timeline. When accessing the table from the path visualization view, filters set in that view will be active in the BGP Updates table.

Columns

A high-level summary of the columns is listed in the following table. For more details about each column, see the detailed descriptions below.

Column

Description

Prefix

Block of IP addresses seen in BGP

AS Path

The routing path leading to the prefix

Communities

Route metadata for grouping routes and applying policies

Update Type

The type of routing change that was advertised

Monitor

BGP Monitor reporting the update

RPKI Status

The validation state of a BGP route based on RPKI

Timestamp (UTC)

Timestamp of the BGP update

Prefix

A BGP prefix is a block of IP addresses that a network advertises via BGP, paired with information about how to reach them. Prefixes are tied to an autonomous system (AS). An AS is a network with its own unique number. When an AS advertises a prefix, it's sharing a path to the IP block, and claiming ownership as well as reachability.

The BGP Update Table can also identify route prepending. Prepending is a method used by network operators to make a route be less preferred by the BGP best path selection algorithm. Because BGP often picks the shortest AS path as the "best" route, prepending lets you increase the number of hops without changing the actual topology. Visibility into route prepending can help identify hijacks that dodge public collectors. These hijacks often use tricks like AS Path prepending to manipulate internet traffic.

AS Path

An AS Path is the trail of networks, or ASs, that packets use to get from their origin to their destination. The BGP protocol determines the best path based on shared routing information. The best path is typically the shortest path, but other factors can affect that.

Communities

BGP communities are an optional tag-like attribute that let you group routes and apply policies. A BGP community is typically specified as a 32-bit value written as 16-bit numbers separated by a colon, such as 65000:123. The first 16 bits typically identify the autonomous system (AS) setting the community. The following 16 bits specify an agreed upon code that carries meaning for downstream routing. There are a few standard communities defined in RFC 1997. These include, "NO_EXPORT" and "NO_ADVERTISE". "NO_EXPORT" indicates that the route is not to be sent beyond your AS. "NO_ADVERTISE" indicates that the route is not to be shared with neighbors.

Update Type

BGP uses two main types of updates: announcements and withdrawals. An announcement update communicates that a route is updated and there is new information to share with peers. This can include a network coming online, a new prefix being added, or changes to a route (such as prepending). A withdrawal update communicates that a prefix can no longer be reached through that network.

Monitor

The Monitor column displays which BGP monitor reported the update message. ThousandEyes BGP monitors are a specialized network of tools and infrastructure designed to track and analyze BGP routing data across the internet. Monitors can help with spotting issues like route hijacks, path changes, or outages that can impact connectivity or performance. Monitors can also include private BGP monitors that you've set up yourself.

RPKI Status

RPKI Status refers to the validation state of a BGP route based on the Resource Public Key Infrastructure (RPKI), a security framework designed to make internet routing more trustworthy. Monitoring RPKI can prevent hijacks or misconfigurations where an AS advertises prefixes which aren't allocated to it. When a router or monitoring system checks a BGP announcement against RPKI, the route gets one of three statuses: Valid, Invalid, and NotFound. To learn more about RPKI statuses, see RPKI.

Timestamp (UTC)

Routers stamp every update they receive, syncing to NTP for accuracy. The BGP Update Table can show a logged route change with a timestamp tied to the ThousandEyes BGP 1-minute update cycle. These timestamps can turn a set of routing changes into a timeline. You can see when a prefix flipped from one AS to another, spot how long an update took to propagate, or determine the start of an outage.

Filters

Filters are located on the top left side of the BGP Update Table. The default filters available for the BGP Update Table are prefix, AS path, and origin AS.

Use the Add Filter menu for additional filters.

When accessing the table from the path visualization view, filters set in that view will be active in the BGP Updates table. These vary according to where in the view the link to the table is accessed.

When accessing the BGP Updates table from the timeline, only the selected prefix and the time range applied to the timeline are carried over. The filters below the timeline are carried over when the BGP Updates table is accessed from the topology view.

Applying Filters to Columns

Filters match any value within the same filter category (OR). Filters must match all values across different filter categories (AND).

Filter for Column

Matches

Prefix

The specified range of IP addresses. Shown by default.

AS Path

Any sequence of AS numbers contained in the path in that order. Includes prepending. Shown by default.

Origin AS

AS Path with the specified AS number as the rightmost value. Shown by default.

Communities

When the value exists within any of the segments. You can suffix or prefix with a colon to specify location in the segment. For example, 100: shows communities that begin with 100, :100 shows communities where 100 is the second or third value.

Monitor

Monitors enabled at any point during the selected time range. Includes private, public, and ThousandEyes monitors.

RPKI Status

Valid, Invalid, NotFound

Update Type

Announcement, Withdrawal

Auto-update

When auto-update is enabled, the data in the list refreshes continuously. To turn auto-update on or off, click the toggle at the top right of the list. Auto-update is enabled by default.

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