Skip to main content

BGP Attributes


BGP attributes are broadly divided into two parts:





  1. Well Known attributes
  2. Optional attributes




Well-known attributes: "MUST" be recognized by all BGP implementations
Optional attributes: May or may not be supported by the BGP implementations





Transitive attributes: BGP process has to accept the path in which it is included and should pass it on to other peers even if these attributes are not supported. Meaning if any optional attribute is not recognized by a BGP implementation, then BGP looks to check if the transitive flag is set. If the transitive flag is set then BGP implementation should accept the attribute and advertise it to its other BGP Peers.





Non-transitive attributes: If the BGP process does not recognize the attribute then it can ignore the update and not advertise the path to its peers. If the transitive flag is not set then BGP implementation can quietly ignore the attribute, it does not have to accept and advertise this attribute to its other peers.





Well known attributes are further subdivided into:





  1. Mandatory
  2. Discretionary




Optional attributes are further divided into:





  1. Transitive
  2. Non-transitive




Well-known Mandatory Attributes
ORIGIN
AS_PATH
NEXT_HOP





Well-known Discretionary Attributes
LOCAL_PREF
ATOMIC_AGGREGATOR





Optional Transitive Attribute
AGGREGATOR
COMMUNITY





Optional non-transitive Attribute
MULTI_EXIT_DISC (MED)
ORIGINATOR_ID
CLUSTER_LIST


Labels:

Comments

Post a Comment

Popular posts from this blog

MITRE ATT&CK - Kerberos Vulnerabilities and Security

From the previous post, the summary of Kerberos authentication process is as below: For the initial authentication, the user’s client machine sends a request to the KDC  Authentication Service (AS) . The request includes details like the user’s username, and the date and time. All information except the username is encrypted using the hash of the user’s password. The KDC AS uses the username to look up its copy of the user’s password hash and uses it to decrypt the rest of the request. If the decryption is successful, that means the client used the correct password hash and the user has successfully authenticated. Once the user is authenticated, the KDC AS sends the user’s client a  ticket granting ticket   (TGT) . The TGT includes a unique session key and a timestamp that specifies how long that session is valid (normally 8 or 10 hours). Importantly, before sending the TGT, the KDC encrypts it using the password hash for a special account, the  KRBTGT account. ...
7 comments
Read more

Checkpoint - Exporting Objects in CSV format

Be it a Network Operations Manager, Security Architect or a Security Auditor, the people up the hierarchy always harangue the Security Engineers to compile the list of firewall objects or rules or policies or the traffic statistics and so on.. This can turn out to be quite hectic especially if there are no built in features to systematically provide the output in a "layman-readable" format. Come, Checkpoint's "Object Explorer..."  which not only provides the output in the "layman-readable" format, but also provides in-built filtering mechanisms, thereby ensuring that the Security Engineer doesn't have to rely on Google for building his scarce Microsoft Excel data filtering skills. The following screenshots will show how easy it is, with Checkpoint R80.10 to generate the firewall configuration inventory. On the SmartConsole Unified Portal, navigate to Menu >> Open Object Explorer... Select the Categories you wish to see in your output: Click o...
Post a Comment
Read more

MITRE ATT&CK - Tools, Attacks and Related - 1

MASSCAN - Mass IP port scanner https://github.com/robertdavidgraham/masscan TeamTNT - Threat group that has primarily targeted cloud and containerized applications. The group has been active since at least Oct 2019 and has mainly focused its efforts on leveraging cloud and container resources to deploy cryptocurrency miners in victim environments. List of Techniques used by TeamTNT can be found here: https://attack.mitre.org/groups/G0139/ Mimikatz - Is a credential dumper capable of obtaining plaintext Windows account logins and passwords, along with many other features that make it useful for testing the security of networks. Golden Ticket Attack - A golden ticket in Active Directory grants the bearer unlimited access. A golden ticket attack abuses the Kerberos protocol, which depends on the use of shared secrets to encrypt and sign messages. One of these secrets is known only to the Key Distribution Center (KDC): the password hash for the KRBTGT user, which is used to issue the Ke...
2 comments
Read more