[c-nsp] full routing table

Elmar K. Bins elmi at 4ever.de
Fri Feb 22 11:42:57 EST 2008


alex at bytemark.co.uk (Alex Howells) wrote:

> Quick question since my Google-fu is failing me: what's the DRAM
> requirement to take a full routing table from a provider these days?

That would depend on your architecture.
My SUP720-3B has it this way:

rt#sh ip bgp summary
BGP router identifier xx.xx.xx.xx, local AS number xx
BGP table version is 139753727, main routing table version 139753727
242874 network entries using 27687636 bytes of memory
753723 path entries using 36178704 bytes of memory
118629/37564 BGP path/bestpath attribute entries using 11862900 bytes of memory
71997 BGP AS-PATH entries using 1861494 bytes of memory
1304 BGP community entries using 53696 bytes of memory
6 BGP extended community entries using 176 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
79436 BGP filter-list cache entries using 953232 bytes of memory
BGP using 78597838 total bytes of memory
241161 received paths for inbound soft reconfiguration
BGP activity 2200840/1956946 prefixes, 2305859991/2305103151 paths, scan interval 60 secs

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd
10.10.10.1      4    xx 9848364    274248 139753727    0    0 27w1d       52428
10.10.10.2      4    xx 10095871   274248 139753727    0    0 27w1d       65672
10.10.10.6      4    xx 6049216   5878297 139753727    0    0 27w1d       18148
10.10.10.11     4    xx 223634063 5884433 139753727    0    0 2w2d       103424
10.10.10.12     4    xx 221680560 5884479 139753727    0    0 2w3d       103409
yy.yy.yy.yy     4    yy 9758289    274225 139753701    0    0 5w6d       169423



We are taking a full feed from yy.yy.yy.yy, but this box filters heavily
(waiting for its XL PFC). soft-reconfiguration is active on all sessions.



This is the neighbor info for the transit peer:

rt#sh ip bgp nei yy.yy.yy.yy
BGP neighbor is yy.yy.yy.yy,  remote AS yy, external link
 Description: TRANSIT-YY
 Member of peer-group UP-YY for session parameters
  BGP version 4, remote router ID yy.yy.yy.yy
  BGP state = Established, up for 5w6d
  Last read 00:00:14, last write 00:00:40, hold time is 180, keepalive interval is 60 seconds
  Neighbor capabilities:
    Route refresh: advertised and received(new)
    Address family IPv4 Unicast: advertised and received
  Message statistics:
    InQ depth is 0
    OutQ depth is 0
                         Sent       Rcvd
    Opens:                 24         15
    Notifications:         17          0
    Updates:              126    9484371
    Keepalives:        274069     274012
    Route Refresh:          0          0
    Total:             274229    9758398
  Default minimum time between advertisement runs is 30 seconds

 For address family: IPv4 Unicast
  BGP table version 139754464, neighbor version 139754446/0
 Output queue size : 0
  Index 4, Offset 0, Mask 0x10
  4 update-group member
  UP-YY peer-group member
  Inbound soft reconfiguration allowed
  Community attribute sent to this neighbor
  Inbound path policy configured
  Outbound path policy configured
  Incoming update prefix filter list is pl-yy-in
  Outgoing update prefix filter list is pl-yy-out
  Incoming update AS path filter list is 2
  Outgoing update AS path filter list is 4
  Route map for incoming advertisements is yy-in
  Route map for outgoing advertisements is yy-out
                                 Sent       Rcvd
  Prefix activity:               ----       ----
    Prefixes Current:               7     169423 (Consumes 19708032 bytes)
    Prefixes Total:                28    4430059
    Implicit Withdraw:             20    3891493
    Explicit Withdraw:              1     369143
    Used as bestpath:             n/a      18099
    Used as multipath:            n/a          0
    Saved (soft-reconfig):        n/a     241161 (Consumes 11575728 bytes)

                                   Outbound    Inbound
  Local Policy Denied Prefixes:    --------    -------
    filter-list:                   27889573          0
    prefix-list                          11    1796865
    AS_PATH loop:                       n/a         34
    Total:                         27889584    1796899
  Number of NLRIs in the update sent: max 1, min 0

  Connections established 11; dropped 10
  Last reset 5w6d, due to Peer closed the session
  External BGP neighbor may be up to 2 hops away.
Connection state is ESTAB, I/O status: 1, unread input bytes: 0
Local host: zz.zz.zz.zz, Local port: 179
Foreign host: yy.yy.yy.yy, Foreign port: 11013

Enqueued packets for retransmit: 0, input: 0  mis-ordered: 0 (0 bytes)

Event Timers (current time is 0x3D4C53C7C):
Timer          Starts    Wakeups            Next
Retrans         62137       1984             0x0
TimeWait            0          0             0x0
AckHold        358398     183495             0x0
SendWnd             0          0             0x0
KeepAlive           1          0             0x0
GiveUp              0          0             0x0
PmtuAger            0          0             0x0
DeadWait            0          0             0x0

iss: 1970806853  snduna: 1971951238  sndnxt: 1971951238     sndwnd:  16384
irs: 4243855748  rcvnxt:  107774782  rcvwnd:      15976  delrcvwnd:    408

SRTT: 300 ms, RTTO: 303 ms, RTV: 3 ms, KRTT: 0 ms
minRTT: 0 ms, maxRTT: 600 ms, ACK hold: 200 ms
Flags: passive open, retransmission timeout, nagle, gen tcbs
  md5

Datagrams (max data segment is 516 bytes):
Rcvd: 605832 (out of order: 1), with data: 549440, total data bytes: 158886329
Sent: 510093 (retransmit: 1984), with data: 60152, total data bytes: 1144384



There's a lot of math to do, since you have prefixes, RIB and RIB
to take into account.

The "Prefixes Current" and "Saved (soft-reconfig)" lines above
should help with the math.


Enjoy,
	Elmi.

-- 

"Hinken ist kein Mangel eines Vergleichs, sondern sollte als wesentliche
 Eigenschaft von Vergleichen angesehen werden."       (Marius Fränzel in desd)

--------------------------------------------------------------[ ELMI-RIPE ]---



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