Why the last AS PATH item always is `I` or `?`? [duplicate] The 2019 Stack Overflow Developer Survey Results Are In Announcing the arrival of Valued Associate #679: Cesar Manara Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)How to understand the output below from BGP?Measuring route processing timeWhy would you want to prevent customer routes being advertised to certain peers?wrong BGP AS number transmittedUnexpected AS-PATH ACL behaviorWhy Connected Routes are not shown as RIB failure in BGP Table?Does the Router running multi routing protocol progresses received the routes will store into the Forwarding table?All routes about a IP in my Router AS-PATH last AS number is IdleTraceroute doesn't show one hop?Juniper router how to check the BGP process port?Why Cisco BGP neighbor command need the remote-as number?
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Why the last AS PATH item always is `I` or `?`? [duplicate]
The 2019 Stack Overflow Developer Survey Results Are In
Announcing the arrival of Valued Associate #679: Cesar Manara
Planned maintenance scheduled April 17/18, 2019 at 00:00UTC (8:00pm US/Eastern)How to understand the output below from BGP?Measuring route processing timeWhy would you want to prevent customer routes being advertised to certain peers?wrong BGP AS number transmittedUnexpected AS-PATH ACL behaviorWhy Connected Routes are not shown as RIB failure in BGP Table?Does the Router running multi routing protocol progresses received the routes will store into the Forwarding table?All routes about a IP in my Router AS-PATH last AS number is IdleTraceroute doesn't show one hop?Juniper router how to check the BGP process port?Why Cisco BGP neighbor command need the remote-as number?
This question already has an answer here:
How to understand the output below from BGP?
2 answers
you see my snapshot from m Juniper Router, I want to find the routes of 114.114.114.114, but there always get Idle or a ?, why:
router bgp juniper
asked Mar 31 at 13:22
244boy244boy
4188
marked as duplicate by Sebastian Wiesinger, Teun Vink♦ Apr 1 at 9:41
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
add a comment |
This question already has an answer here:
How to understand the output below from BGP?
2 answers
you see my snapshot from m Juniper Router, I want to find the routes of 114.114.114.114, but there always get Idle or a ?, why:
router bgp juniper
asked Mar 31 at 13:22
244boy244boy
4188
marked as duplicate by Sebastian Wiesinger, Teun Vink♦ Apr 1 at 9:41
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
add a comment |
This question already has an answer here:
How to understand the output below from BGP?
2 answers
you see my snapshot from m Juniper Router, I want to find the routes of 114.114.114.114, but there always get Idle or a ?, why:
router bgp juniper
asked Mar 31 at 13:22
244boy244boy
4188
This question already has an answer here:
How to understand the output below from BGP?
2 answers
you see my snapshot from m Juniper Router, I want to find the routes of 114.114.114.114, but there always get Idle or a ?, why:
This question already has an answer here:
How to understand the output below from BGP?
2 answers
router bgp juniper
router bgp juniper
asked Mar 31 at 13:22
244boy244boy
4188
asked Mar 31 at 13:22
244boy244boy
4188
asked Mar 31 at 13:22
244boy244boy
4188
asked Mar 31 at 13:22
244boy244boy
4188
asked Mar 31 at 13:22
244boy244boy
4188
4188
marked as duplicate by Sebastian Wiesinger, Teun Vink♦ Apr 1 at 9:41
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
marked as duplicate by Sebastian Wiesinger, Teun Vink♦ Apr 1 at 9:41
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
add a comment |
add a comment |
3 Answers
3
active
oldest
votes
This tells you how this prefix was learned by BGP.
This is an attribute called origin, which may help BGP decide the preferred path to take (if all higher weight attributes are tied - local-preference, weight, as-path etc.)
"I"- tells you the NLRI was introduced into BGP directly using the "network" command (Not sure why its referred to as "IGP", if someone knows please leave a comment).
"?"- tells you the NLRI was redistributed into BGP from another protocol.
answered Mar 31 at 16:10
sergeyrarsergeyrar
616110
add a comment |
"I" Represented IGP. That mean iBGP is being used.
Internal Border Gateway Protocol (iBGP) is a term used to describe an area of BGP operation that runs within an organization or autonomous system. Internal BGP is a method employed to provide more information to your internal routers. iBGP could be said to be one of the peers of BGP routers.
answered Mar 31 at 13:37
serverAdmin123serverAdmin123
3397
Not true, it does not mean iBGP
– sergeyrar
Mar 31 at 16:12
can you explain??
– serverAdmin123
Mar 31 at 18:30
IGP != iBGP (BGP is EGP)
– sergeyrar
Mar 31 at 19:01
add a comment |
I try to answer this question :-
For a route to be announced by BGP , there is a condition that must be satisfied which is that the 'route' must be present in the routing table of originating router. If a 'route' is present in the routing table of router , then it can advertise that route via BGP.
Now router can know about that 'route' via Interior Gateway Protocol. In this case we can use network command (or prefix list in Juniper and then call that prefix list in export policy) to announce that route to other peer. In this case when this router advertise this route it set 'I' with that route meaning that the route was known to Router via Interior Gateway Protocol in AS (it may be OSPF , IS-IS , EIGRP).
Now for the case of '?' against BGP routes which comes with possibility that your router has learnt that route but it doesn't know the source of that 'route'. Meaning 'route' has been redistributed from IGP to some other IGP (like from OSPF to ISIS). In that case , router will think that ' I don't know how originally announce / own this route in the IGP domain as it has been redistributed . Again you can use network or (prefix list in Juniper and then call that prefix list in export policy) to advertise that route to other peers. But in this when the router advertise this route it set '?' to prefix it advertise to other peers.
answered Mar 31 at 18:53
NABEEL NASIRNABEEL NASIR
2018
add a comment |
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
This tells you how this prefix was learned by BGP.
This is an attribute called origin, which may help BGP decide the preferred path to take (if all higher weight attributes are tied - local-preference, weight, as-path etc.)
"I"- tells you the NLRI was introduced into BGP directly using the "network" command (Not sure why its referred to as "IGP", if someone knows please leave a comment).
"?"- tells you the NLRI was redistributed into BGP from another protocol.
answered Mar 31 at 16:10
sergeyrarsergeyrar
616110
add a comment |
This tells you how this prefix was learned by BGP.
This is an attribute called origin, which may help BGP decide the preferred path to take (if all higher weight attributes are tied - local-preference, weight, as-path etc.)
"I"- tells you the NLRI was introduced into BGP directly using the "network" command (Not sure why its referred to as "IGP", if someone knows please leave a comment).
"?"- tells you the NLRI was redistributed into BGP from another protocol.
answered Mar 31 at 16:10
sergeyrarsergeyrar
616110
add a comment |
This tells you how this prefix was learned by BGP.
This is an attribute called origin, which may help BGP decide the preferred path to take (if all higher weight attributes are tied - local-preference, weight, as-path etc.)
"I"- tells you the NLRI was introduced into BGP directly using the "network" command (Not sure why its referred to as "IGP", if someone knows please leave a comment).
"?"- tells you the NLRI was redistributed into BGP from another protocol.
answered Mar 31 at 16:10
sergeyrarsergeyrar
616110
This tells you how this prefix was learned by BGP.
This is an attribute called origin, which may help BGP decide the preferred path to take (if all higher weight attributes are tied - local-preference, weight, as-path etc.)
"I"- tells you the NLRI was introduced into BGP directly using the "network" command (Not sure why its referred to as "IGP", if someone knows please leave a comment).
"?"- tells you the NLRI was redistributed into BGP from another protocol.
answered Mar 31 at 16:10
sergeyrarsergeyrar
616110
answered Mar 31 at 16:10
sergeyrarsergeyrar
616110
answered Mar 31 at 16:10
sergeyrarsergeyrar
616110
answered Mar 31 at 16:10
sergeyrarsergeyrar
616110
616110
add a comment |
add a comment |
"I" Represented IGP. That mean iBGP is being used.
Internal Border Gateway Protocol (iBGP) is a term used to describe an area of BGP operation that runs within an organization or autonomous system. Internal BGP is a method employed to provide more information to your internal routers. iBGP could be said to be one of the peers of BGP routers.
answered Mar 31 at 13:37
serverAdmin123serverAdmin123
3397
Not true, it does not mean iBGP
– sergeyrar
Mar 31 at 16:12
can you explain??
– serverAdmin123
Mar 31 at 18:30
IGP != iBGP (BGP is EGP)
– sergeyrar
Mar 31 at 19:01
add a comment |
"I" Represented IGP. That mean iBGP is being used.
Internal Border Gateway Protocol (iBGP) is a term used to describe an area of BGP operation that runs within an organization or autonomous system. Internal BGP is a method employed to provide more information to your internal routers. iBGP could be said to be one of the peers of BGP routers.
answered Mar 31 at 13:37
serverAdmin123serverAdmin123
3397
Not true, it does not mean iBGP
– sergeyrar
Mar 31 at 16:12
can you explain??
– serverAdmin123
Mar 31 at 18:30
IGP != iBGP (BGP is EGP)
– sergeyrar
Mar 31 at 19:01
add a comment |
"I" Represented IGP. That mean iBGP is being used.
Internal Border Gateway Protocol (iBGP) is a term used to describe an area of BGP operation that runs within an organization or autonomous system. Internal BGP is a method employed to provide more information to your internal routers. iBGP could be said to be one of the peers of BGP routers.
answered Mar 31 at 13:37
serverAdmin123serverAdmin123
3397
"I" Represented IGP. That mean iBGP is being used.
Internal Border Gateway Protocol (iBGP) is a term used to describe an area of BGP operation that runs within an organization or autonomous system. Internal BGP is a method employed to provide more information to your internal routers. iBGP could be said to be one of the peers of BGP routers.
answered Mar 31 at 13:37
serverAdmin123serverAdmin123
3397
answered Mar 31 at 13:37
serverAdmin123serverAdmin123
3397
answered Mar 31 at 13:37
serverAdmin123serverAdmin123
3397
answered Mar 31 at 13:37
serverAdmin123serverAdmin123
3397
3397
Not true, it does not mean iBGP
– sergeyrar
Mar 31 at 16:12
can you explain??
– serverAdmin123
Mar 31 at 18:30
IGP != iBGP (BGP is EGP)
– sergeyrar
Mar 31 at 19:01
add a comment |
Not true, it does not mean iBGP
– sergeyrar
Mar 31 at 16:12
can you explain??
– serverAdmin123
Mar 31 at 18:30
IGP != iBGP (BGP is EGP)
– sergeyrar
Mar 31 at 19:01
Not true, it does not mean iBGP
– sergeyrar
Mar 31 at 16:12
Not true, it does not mean iBGP
– sergeyrar
Mar 31 at 16:12
can you explain??
– serverAdmin123
Mar 31 at 18:30
can you explain??
– serverAdmin123
Mar 31 at 18:30
IGP != iBGP (BGP is EGP)
– sergeyrar
Mar 31 at 19:01
IGP != iBGP (BGP is EGP)
– sergeyrar
Mar 31 at 19:01
add a comment |
I try to answer this question :-
For a route to be announced by BGP , there is a condition that must be satisfied which is that the 'route' must be present in the routing table of originating router. If a 'route' is present in the routing table of router , then it can advertise that route via BGP.
Now router can know about that 'route' via Interior Gateway Protocol. In this case we can use network command (or prefix list in Juniper and then call that prefix list in export policy) to announce that route to other peer. In this case when this router advertise this route it set 'I' with that route meaning that the route was known to Router via Interior Gateway Protocol in AS (it may be OSPF , IS-IS , EIGRP).
Now for the case of '?' against BGP routes which comes with possibility that your router has learnt that route but it doesn't know the source of that 'route'. Meaning 'route' has been redistributed from IGP to some other IGP (like from OSPF to ISIS). In that case , router will think that ' I don't know how originally announce / own this route in the IGP domain as it has been redistributed . Again you can use network or (prefix list in Juniper and then call that prefix list in export policy) to advertise that route to other peers. But in this when the router advertise this route it set '?' to prefix it advertise to other peers.
answered Mar 31 at 18:53
NABEEL NASIRNABEEL NASIR
2018
add a comment |
I try to answer this question :-
For a route to be announced by BGP , there is a condition that must be satisfied which is that the 'route' must be present in the routing table of originating router. If a 'route' is present in the routing table of router , then it can advertise that route via BGP.
Now router can know about that 'route' via Interior Gateway Protocol. In this case we can use network command (or prefix list in Juniper and then call that prefix list in export policy) to announce that route to other peer. In this case when this router advertise this route it set 'I' with that route meaning that the route was known to Router via Interior Gateway Protocol in AS (it may be OSPF , IS-IS , EIGRP).
Now for the case of '?' against BGP routes which comes with possibility that your router has learnt that route but it doesn't know the source of that 'route'. Meaning 'route' has been redistributed from IGP to some other IGP (like from OSPF to ISIS). In that case , router will think that ' I don't know how originally announce / own this route in the IGP domain as it has been redistributed . Again you can use network or (prefix list in Juniper and then call that prefix list in export policy) to advertise that route to other peers. But in this when the router advertise this route it set '?' to prefix it advertise to other peers.
answered Mar 31 at 18:53
NABEEL NASIRNABEEL NASIR
2018
add a comment |
I try to answer this question :-
For a route to be announced by BGP , there is a condition that must be satisfied which is that the 'route' must be present in the routing table of originating router. If a 'route' is present in the routing table of router , then it can advertise that route via BGP.
Now router can know about that 'route' via Interior Gateway Protocol. In this case we can use network command (or prefix list in Juniper and then call that prefix list in export policy) to announce that route to other peer. In this case when this router advertise this route it set 'I' with that route meaning that the route was known to Router via Interior Gateway Protocol in AS (it may be OSPF , IS-IS , EIGRP).
Now for the case of '?' against BGP routes which comes with possibility that your router has learnt that route but it doesn't know the source of that 'route'. Meaning 'route' has been redistributed from IGP to some other IGP (like from OSPF to ISIS). In that case , router will think that ' I don't know how originally announce / own this route in the IGP domain as it has been redistributed . Again you can use network or (prefix list in Juniper and then call that prefix list in export policy) to advertise that route to other peers. But in this when the router advertise this route it set '?' to prefix it advertise to other peers.
answered Mar 31 at 18:53
NABEEL NASIRNABEEL NASIR
2018
I try to answer this question :-
For a route to be announced by BGP , there is a condition that must be satisfied which is that the 'route' must be present in the routing table of originating router. If a 'route' is present in the routing table of router , then it can advertise that route via BGP.
Now router can know about that 'route' via Interior Gateway Protocol. In this case we can use network command (or prefix list in Juniper and then call that prefix list in export policy) to announce that route to other peer. In this case when this router advertise this route it set 'I' with that route meaning that the route was known to Router via Interior Gateway Protocol in AS (it may be OSPF , IS-IS , EIGRP).
Now for the case of '?' against BGP routes which comes with possibility that your router has learnt that route but it doesn't know the source of that 'route'. Meaning 'route' has been redistributed from IGP to some other IGP (like from OSPF to ISIS). In that case , router will think that ' I don't know how originally announce / own this route in the IGP domain as it has been redistributed . Again you can use network or (prefix list in Juniper and then call that prefix list in export policy) to advertise that route to other peers. But in this when the router advertise this route it set '?' to prefix it advertise to other peers.
answered Mar 31 at 18:53
NABEEL NASIRNABEEL NASIR
2018
answered Mar 31 at 18:53
NABEEL NASIRNABEEL NASIR
2018
answered Mar 31 at 18:53
NABEEL NASIRNABEEL NASIR
2018
answered Mar 31 at 18:53
NABEEL NASIRNABEEL NASIR
2018
2018
add a comment |
add a comment |
