Recently, there have been a number of occurrences of corrupt optional, transitive attributes being sent via BGP into the Internet. Routers that do not recognize the optional attribute ignore them and pass them along. The first router along the path that does understand the attribute and determines it to be corrupt will send a NOTIFICATION and close the BGP session. One such type of optional, transitive attribute with sparse vendor support is ATTR_SET (type code 128), as defined in draft-ietf-l3vpn-ibgp. Note that Junos 8.x and earlier does not include support for 4-byte ASNs and therefore would not recognize corruption in attributes specific to 4-byte ASNs.