From: George Goglidze (goglidze@gmail.com)
Date: Mon Dec 10 2007 - 18:35:01 ART
Hi Dane,
I did not know pim dense mode would behave that way either,
I thought it would flood on interfaces where PIM is enabled only.
And as for debug ip packet output, I don't know why you're not able to see
anything,
as it worked for me just fine disabling mroute-cache and cef just in case.
Good luck,
On Dec 10, 2007 5:31 PM, Dane Newman <dnewman@datasc.com> wrote:
> George,
>
> Thanks for some reasons I can't get my debug to show up on R4 so even
> after doing no ip route-cache on the interface so I would have not found
> that. That really is interesting behaviour with dense mode that it does not
> care what interface you source it from it just floods it out everyone and
> now it does make sense the why the router was able to respond to the ping.
> Thanks a ton!
>
> Dane
>
>
>
> On 12/10/07, George Goglidze <goglidze@gmail.com> wrote:
> >
> > Hi Dane,
> >
> > I've done some homework, and here are the results.
> >
> > it works that way because you of the nature of DENSE mode pim.
> >
> > turn on the debug ip packet on R4 and make a ping,
> > we'll see folloing (I've got deb ip packet):
> >
> > R4#ping 225.25.25.25 source f0/0
> >
> > Type escape sequence to abort.
> > Sending 1, 100-byte ICMP Echos to 225.25.25.25, timeout is 2 seconds:
> > Packet sent with a source address of 163.1.4.1
> >
> > *Mar 1 00:05: 12.067: IP: s=163.1.4.1 (local), d= 225.25.25.25(FastEthernet0/0), len 100, sending broad/multicast
> > *Mar 1 00:05:12.067: IP: s=163.1.54.1 (local), d= 225.25.25.25(Serial1/0), len 100, sending broad/multicast
> > *Mar 1 00:05:12.067: IP: s= 163.1.45.1 (local), d=225.25.25.25(Serial1/1), len 100, sending broad/multicast
> > *Mar 1 00:05:12.459: IP: s= 163.1.4.1 (local), d= 224.0.1.40(FastEthernet0/0), len 28, sending broad/multicast
> >
> >
> >
> > As you see on R4, it's being sent out from all interfaces, and it
> > actually takes as a source the interface IP address when it sends the
> > packet, although we have done it with source f0/0.
> >
> > and now on R5 we see this at the same moment: (I've got deb ip packet,
> > deb ip mpacket)
> >
> > *Mar 1 00:16:38.443: IP: tableid=0, s= 163.1.45.2 (local), d=163.1.45.1(Serial1/1), routed via RIB
> > *Mar 1 00:16:38.447: IP: s= 163.1.45.2 (local), d=163.1.45.1(Serial1/1), len 100, sending
> > *Mar 1 00:16:38.451 : IP(0): s= 163.1.45.1 (Serial1/1) d=225.25.25.25(FastEthernet0/0) id=23, ttl=254, prot=1, len=100(100), mforward
> > *Mar 1 00:16: 38.523: IP: s= 163.1.54.1 (Serial1/0), d= 225.25.25.25,
> > len 100, unroutable
> >
> > As you see we received multicast traffic from two sources:
> > 1) 163.1.45.1 and another 163.1.54.1
> > and later we see unroutable for s 163.1.54.1 , now this happens because
> > we have no PIM enabled on that interface.
> >
> > 2) we see that the answer is succesfully sent to 163.1.45.1 which is ok
> > because it passed the RPF check.
> >
> >
> > I think when in dense mode, and when you do ping with source whatever,
> > router does not care about that source, and just sends mcast traffic out
> > all interfaces with their corresponding IP
> > addresses as the source.
> > hence the behavior, the RPF check is fine.
> >
> > now try do the same on sparce-mode routers,
> > and make one of the routers RP.
> >
> > it will definitely fail.
> >
> > Hope this helps,
> >
> > Regards,
> >
> >
> >
> >
> >
> >
> >
> >
> > On Dec 10, 2007 4:06 PM, George Goglidze <goglidze@gmail.com> wrote:
> >
> > > Hi Mr. Newman,
> > >
> > > Sorry didn't notice pim config on R5 E0/0.
> > > and as well that you did ping with source e0/1.
> > >
> > > Then it's fine, you're right it should've failed.
> > >
> > > although from debug output:
> > >
> > > Rack1R5#debug ip mpack
> > > IP multicast packets debugging is on
> > > *Mar 2 11:31:25.119: IP(0): s=163.1.45.4 (Serial0/1)
> > > d=225.25.25.25(Ethernet0/0) id=127, ttl=254, prot=1, len=100(100),
> > >
> > >
> > > for some reason it still sends multicast traffic with source
> > > 163.1.45.4 which is your PTP link.
> > >
> > > that's why it's working.
> > >
> > > so the question doesn't lie in why RPF does not work, but the question
> > > is why it sends traffic with source of Serial interface and not the e0/1
> > > interface.
> > >
> > > I'll lab it up, hope will find something out.
> > >
> > > Will reply you as soon as I have some new info.
> > >
> > > Regards,
> > >
> > >
> > > Now after you've added pim dense mode on R4 E0/0
> > >
> > >
> > > On Dec 10, 2007 3:57 PM, Dane Newman <dnewman@datasc.com> wrote:
> > >
> > > > Mr Godlidze,
> > > >
> > > >
> > > > Thank you for the response.
> > > > R4:
> > > > interface Ethernet0/1
> > > > ip address 163.1.4.4 255.255.255.0
> > > > ip pim dense-mode
> > > > half-duplex
> > > >
> > > > I thought ip pim dense-mode was all I needed to do to enable
> > > > multicast on the e0/1 interface? Am I missing something? When i was pinging
> > > > I was sourcing from e0/1 not e0/0 cause as per the lab multicast wass not
> > > > enabled on e0/0 (vlan 42) only vlan 4 which is e0/1.
> > > >
> > > >
> > > > Also
> > > >
> > > > R5:
> > > > interface Ethernet0/0
> > > > ip address 163.1.5.5 255.255.255.0
> > > > ip pim dense-mode
> > > > ip igmp join-group 225.25.25.25
> > > > half-duplex
> > > >
> > > > end
> > > >
> > > > Again I just have pim dense mode enabled and the igmp group joined
> > > > to repond to pings. Was there something else I needed to do?
> > > >
> > > >
> > > >
> > > >
> > > > On 12/10/07, George Goglidze <goglidze@gmail.com > wrote:
> > > > >
> > > > > Hi There,
> > > > >
> > > > > You don't have PIM neabled on the Ethernet interface of R4,
> > > > > so when you make a ping 225.25.25.25 source e0/0
> > > > > it does not really do ping from e0/0 it makes ping from the
> > > > > point-to-point interface,
> > > > > which is the one you have enabled pim dense-mode.
> > > > >
> > > > > and the other router does answer because RPF check is as a matter
> > > > > of fact SUCCESSFULL,
> > > > > becuase your source is as we can perfectly see from debug output:
> > > > >
> > > > > Rack1R5#debug ip mpack
> > > > > IP multicast packets debugging is on
> > > > > *Mar 2 11:31:25.119: IP(0): s=163.1.45.4 (Serial0/1)
> > > > > d=225.25.25.25(Ethernet0/0) id=127, ttl=254, prot=1, len=100(100),
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > SOURCE: 163.1.45.4
> > > > > and this is correct RPF through p-t-p link.
> > > > >
> > > > >
> > > > > Regards,
> > > > >
> > > > >
> > > > > On Dec 10, 2007 3:22 PM, Grabler, Ross (IT) <Ross.Grabler@morganstanley.com
> > > > > > wrote:
> > > > >
> > > > > > Send
> > > > > > Sh ip mroute 225.25.25.25
> > > > > > sh ip mroute 225.25.25.25 count
> > > > > > and sh ip rpf (what ever the source is).
> > > > > > Sh ip pim neig
> > > > > >
> > > > > > Also your point to point is not in mcast.
> > > > > >
> > > > > >
> > > > > > Ross Grabler
> > > > > > Technology
> > > > > > 1 Pierrepont Plaza, 12th Floor | Brooklyn, NY 11201
> > > > > > Phone: +1 718 754-5693
> > > > > > Ross.Grabler@morganstanley.com
> > > > > >
> > > > > > -----Original Message-----
> > > > > > From: nobody@groupstudy.com [mailto: nobody@groupstudy.com] On
> > > > > > Behalf Of
> > > > > > Dane Newman
> > > > > > Sent: Monday, December 10, 2007 8:44 AM
> > > > > > To: ccielab@groupstudy.com
> > > > > > Subject: Multicast issue
> > > > > >
> > > > > > *Hello Experts*
> > > > > > **
> > > > > > **
> > > > > > *My problem is I believe I should be having an RPF failure and
> > > > > > have to
> > > > > > create a static mroute. The problem is its working and I don't
> > > > > > understand why its working when it should not which is a problem
> > > > > > in
> > > > > > itself. Its probably some silly error or just some concept I
> > > > > > don't
> > > > > > under/stand grasp yet. This is from internetwork expert lab 9
> > > > > > problem
> > > > > > 6.1.*
> > > > > > **
> > > > > > **
> > > > > > *I have R5 which and R4 connected between the frame relay
> > > > > > network
> > > > > > 163.1.54.0/24 and a point to point link 163.1.45.0/24 *
> > > > > > **
> > > > > > *vlan 4 is connected to e0/1 on R4 and vlan 5 is connected to
> > > > > > e0/0 on
> > > > > > R5*
> > > > > > **
> > > > > > *Below is the show ip route to each of the vlans from the other
> > > > > > respective router. Traffic is going across the frame relay link
> > > > > > from
> > > > > > the output. *
> > > > > >
> > > > > > Rack1R4#show ip route 163.1.5.0
> > > > > > Routing entry for 163.1.5.0/24
> > > > > > Known via "ospf 1", distance 110, metric 74, type intra area
> > > > > > Redistributing via rip
> > > > > > Advertised by rip metric 5
> > > > > > Last update from 163.1.54.5 on Serial0/0, 00:27:00 ago
> > > > > > Routing Descriptor Blocks:
> > > > > > * 163.1.54.5, from 5.5.5.5, 00:27:00 ago, via Serial0/0
> > > > > > Route metric is 74, traffic share count is 1
> > > > > >
> > > > > > Rack1R5#show ip route 163.1.4.0
> > > > > > Routing entry for 163.1.4.0/24
> > > > > > Known via "ospf 1", distance 110, metric 74, type intra area
> > > > > > Last update from 163.1.54.4 on Serial0/0.54, 00:20:34 ago
> > > > > > Routing Descriptor Blocks:
> > > > > > * 163.1.54.4, from 4.4.4.4, 00:20:34 ago, via Serial0/0.54
> > > > > > Route metric is 74, traffic share count is 1
> > > > > >
> > > > > >
> > > > > >
> > > > > > *When I ping from R4 to the group it pings back but it should be
> > > > > > an RPF
> > > > > > failure because it should use the frame relay link but the debug
> > > > > > below
> > > > > > after the ping shows it used the point to point link*
> > > > > >
> > > > > >
> > > > > > Rack1R4#ping 225.25.25.25 source e0/1
> > > > > >
> > > > > > Type escape sequence to abort.
> > > > > > Sending 1, 100-byte ICMP Echos to 225.25.25.25, timeout is 2
> > > > > > seconds:
> > > > > > Packet sent with a source address of 163.1.4.4
> > > > > >
> > > > > > Reply to request 0 from 163.1.45.5, 40 ms
> > > > > >
> > > > > >
> > > > > >
> > > > > > Rack1R5#debug ip mpack
> > > > > > IP multicast packets debugging is on
> > > > > > *Mar 2 11:31:25.119 : IP(0): s=163.1.45.4 (Serial0/1)
> > > > > > d=225.25.25.25(Ethernet0/0) id=127, ttl=254, prot=1,
> > > > > > len=100(100),
> > > > > > mforward
> > > > > >
> > > > > > *I thought from my limited knowledge multicast routing follows
> > > > > > the
> > > > > > unicast routing table but how is it then going through the point
> > > > > > to
> > > > > > point link?*
> > > > > > **
> > > > > > **
> > > > > > **
> > > > > > *Here are the full configs*
> > > > > >
> > > > > >
> > > > > > R4
> > > > > > version 12.4
> > > > > > service timestamps debug datetime msec
> > > > > > service timestamps log datetime msec
> > > > > > no service password-encryption
> > > > > > !
> > > > > > hostname Rack1R4
> > > > > > !
> > > > > > boot-start-marker
> > > > > > boot-end-marker
> > > > > > !
> > > > > > enable password cisco
> > > > > > !
> > > > > > no aaa new-model
> > > > > > !
> > > > > > !
> > > > > > ip cef
> > > > > > no ip domain lookup
> > > > > > !
> > > > > > !
> > > > > > ip multicast-routing
> > > > > > !
> > > > > > !
> > > > > > !
> > > > > > key chain 1
> > > > > > key 1
> > > > > > key-string CISCO
> > > > > > !
> > > > > > username Rack1R5 password 0 CISCO
> > > > > > !
> > > > > >
> > > > > > !
> > > > > > interface Loopback0
> > > > > > ip address 150.1.4.4 255.255.255.0
> > > > > > ip ospf network point-to-point
> > > > > > ip ospf 1 area 0
> > > > > > !
> > > > > > interface Ethernet0/0
> > > > > > ip address 192.10.1.4 255.255.255.0
> > > > > > ip rip authentication mode md5
> > > > > > ip rip authentication key-chain 1
> > > > > > no ip route-cache cef
> > > > > > no ip route-cache
> > > > > > ip summary-address rip 163.1.0.0 255.255.192.0 ip
> > > > > > summary-address rip
> > > > > > 150.1.0.0 255.255.240.0 half-duplex !
> > > > > > interface Serial0/0
> > > > > > ip address 163.1.54.4 255.255.255.0
> > > > > > encapsulation frame-relay
> > > > > > ip ospf network point-to-point
> > > > > > frame-relay map ip 163.1.54.5 405 broadcast frame-relay
> > > > > > interface-dlci
> > > > > > 405
> > > > > > class KEEPALIVE
> > > > > > no frame-relay inverse-arp
> > > > > > !
> > > > > > interface Ethernet0/1
> > > > > > ip address 163.1.4.4 255.255.255.0
> > > > > > ip pim dense-mode
> > > > > > half-duplex
> > > > > > !
> > > > > > interface Serial0/1
> > > > > > ip address 163.1.45.4 255.255.255.0
> > > > > > ip pim dense-mode
> > > > > > encapsulation ppp
> > > > > > clock rate 56000
> > > > > > ppp authentication pap
> > > > > > ppp pap sent-username Rack1R4 password 0 CISCO !
> > > > > > router ospf 1
> > > > > > router-id 4.4.4.4
> > > > > > log-adjacency-changes
> > > > > > redistribute rip metric 50 subnets
> > > > > > network 163.1.4.4 0.0.0.0 area 0
> > > > > > network 163.1.54.4 0.0.0.0 area 0
> > > > > > !
> > > > > > router rip
> > > > > > version 2
> > > > > > redistribute ospf 1 metric 5
> > > > > > passive-interface default
> > > > > > no passive-interface Ethernet0/0
> > > > > > no passive-interface Ethernet0/1
> > > > > > no passive-interface Serial0/1
> > > > > > network 163.1.0.0
> > > > > > network 192.10.1.0
> > > > > > distribute-list prefix SUM out Ethernet0/0 distribute-list 8
> > > > > > in
> > > > > > Ethernet0/0 distance 109 163.1.45.5 0.0.0.0 4 no auto-summary
> > > > > > !
> > > > > > router bgp 65004
> > > > > > no synchronization
> > > > > > bgp log-neighbor-changes
> > > > > > bgp confederation identifier 200
> > > > > > bgp confederation peers 65005 65007
> > > > > > neighbor 163.1.45.5 remote-as 65005
> > > > > > neighbor 192.10.1.254 remote-as 254
> > > > > > neighbor 192.10.1.254 password CISCO
> > > > > > no auto-summary
> > > > > > !
> > > > > > ip http server
> > > > > > no ip http secure-server
> > > > > > !
> > > > > > ip forward-protocol nd
> > > > > > !
> > > > > > !
> > > > > > !
> > > > > > ip prefix-list FILTER seq 5 permit 163.1.45.5/32 !
> > > > > > ip prefix-list SUM seq 5 permit 150.1.0.0/20 ip prefix-list SUM
> > > > > > seq 10
> > > > > > permit 163.1.0.0/18 !
> > > > > > map-class frame-relay KEEPALIVE
> > > > > > frame-relay end-to-end keepalive mode reply access-list 4
> > > > > > permit
> > > > > > 150.1.7.0 access-list 4 permit 163.1.7.0 access-list 4 permit
> > > > > > 10.3.3.0
> > > > > > 0.0.0.255 access-list 4 permit 163.1.0.0 0.0.0.255 access-list 4
> > > > > > permit
> > > > > > 163.1.3.0 0.0.0.255 access-list 4 permit 163.1.7.0 0.0.0.255
> > > > > > access-list 6 deny 10.3.3.3
> > > > > > access-list 6 deny 163.1.0.0 0.0.0.255
> > > > > > access-list 6 deny 163.1.3.0 0.0.0.255
> > > > > > access-list 6 permit any
> > > > > > access-list 8 deny any
> > > > > > access-list 50 permit 163.1.57.0
> > > > > > !
> > > > > > route-map OSPF->RIP deny 10
> > > > > > match tag 120 20
> > > > > > !
> > > > > > route-map OSPF->RIP permit 20
> > > > > > set tag 10
> > > > > > !
> > > > > > route-map RIP->OSPF deny 10
> > > > > > match tag 110 10
> > > > > > !
> > > > > > route-map RIP->OSPF permit 20
> > > > > > set tag 20
> > > > > > !
> > > > > > !
> > > > > > !
> > > > > > control-plane
> > > > > > !
> > > > > >
> > > > > > line con 0
> > > > > > exec-timeout 0 0
> > > > > > privilege level 15
> > > > > > logging synchronous
> > > > > > line aux 0
> > > > > > exec-timeout 0 0
> > > > > > privilege level 15
> > > > > > line vty 0 4
> > > > > > password cisco
> > > > > > login
> > > > > > !
> > > > > > !
> > > > > > end
> > > > > >
> > > > > >
> > > > > > R5:
> > > > > > version 12.4
> > > > > > service timestamps debug datetime msec
> > > > > > service timestamps log datetime msec
> > > > > > no service password-encryption
> > > > > > !
> > > > > > hostname Rack1R5
> > > > > > !
> > > > > > boot-start-marker
> > > > > > boot-end-marker
> > > > > > !
> > > > > > enable password cisco
> > > > > > !
> > > > > > no aaa new-model
> > > > > > !
> > > > > > !
> > > > > > ip cef
> > > > > > no ip domain lookup
> > > > > > !
> > > > > > !
> > > > > > ip multicast-routing
> > > > > > !
> > > > > > username Rack1R4 password 0 CISCO
> > > > > > !
> > > > > > !
> > > > > > interface Loopback0
> > > > > > ip address 150.1.5.5 255.255.255.0
> > > > > > ip ospf network point-to-point
> > > > > > ip ospf 1 area 0
> > > > > > !
> > > > > > interface Tunnel15
> > > > > > ip address 163.1.15.5 255.255.255.0
> > > > > > ip ospf mtu-ignore
> > > > > > tunnel source Serial0/0.35
> > > > > > tunnel destination 150.1.1.1
> > > > > > !
> > > > > > interface Ethernet0/0
> > > > > > ip address 163.1.5.5 255.255.255.0
> > > > > > ip pim dense-mode
> > > > > > ip igmp join-group 225.25.25.25
> > > > > > half-duplex
> > > > > > !
> > > > > > interface Serial0/0
> > > > > > no ip address
> > > > > > encapsulation frame-relay
> > > > > > no ip route-cache cef
> > > > > > no ip route-cache
> > > > > > no frame-relay inverse-arp
> > > > > > !
> > > > > > interface Serial0/0.35 point-to-point
> > > > > > ip address 163.1.35.5 255.255.255.0
> > > > > > no ip route-cache
> > > > > > frame-relay interface-dlci 503
> > > > > > !
> > > > > > interface Serial0/0.54 point-to-point
> > > > > > ip address 163.1.54.5 255.255.255.0
> > > > > > no ip route-cache
> > > > > > frame-relay interface-dlci 504
> > > > > > class KEEPALIVE
> > > > > > !
> > > > > > interface Ethernet0/1
> > > > > > ip address 163.1.57.5 255.255.255.0
> > > > > > half-duplex
> > > > > > !
> > > > > > interface Serial0/1
> > > > > > ip address 163.1.45.5 255.255.255.0
> > > > > > ip pim dense-mode
> > > > > > encapsulation ppp
> > > > > > ppp authentication pap
> > > > > > ppp pap sent-username Rack1R5 password 0 CISCO !
> > > > > > router ospf 1
> > > > > > router-id 5.5.5.5
> > > > > > log-adjacency-changes
> > > > > > area 0 range 150.1.4.0 255.255.254.0
> > > > > > redistribute rip
> > > > > > network 163.1.5.5 0.0.0.0 area 0
> > > > > > network 163.1.15.5 0.0.0.0 area 0
> > > > > > network 163.1.35.5 0.0.0.0 area 1
> > > > > > network 163.1.54.5 0.0.0.0 area 0
> > > > > > !
> > > > > > router rip
> > > > > > version 2
> > > > > > passive-interface default
> > > > > > no passive-interface Ethernet0/1
> > > > > > no passive-interface Serial0/1
> > > > > > network 163.1.0.0
> > > > > > default-information originate
> > > > > > distribute-list prefix DEFAULTROUTE out Ethernet0/1 distance
> > > > > > 109
> > > > > > 0.0.0.0 255.255.255.255 4 no auto-summary !
> > > > > > router bgp 65005
> > > > > > no synchronization
> > > > > > bgp log-neighbor-changes
> > > > > > bgp confederation identifier 200
> > > > > > bgp confederation peers 65004 65007
> > > > > > neighbor 163.1.35.3 remote-as 300
> > > > > > neighbor 163.1.45.4 remote-as 65004
> > > > > > neighbor 163.1.57.7 remote-as 65007
> > > > > > no auto-summary
> > > > > > !
> > > > > > ip http server
> > > > > > no ip http secure-server
> > > > > > !
> > > > > > ip forward-protocol nd
> > > > > > !
> > > > > > !
> > > > > > !
> > > > > > ip prefix-list DEFAULTROUTE seq 5 permit 0.0.0.0/0 !
> > > > > > map-class frame-relay KEEPALIVE
> > > > > > frame-relay end-to-end keepalive mode request access-list 4
> > > > > > permit
> > > > > > 150.1.7.0 access-list 4 permit 163.1.7.0 access-list 4 permit
> > > > > > 192.10.1.0
> > > > > > access-list 4 permit 10.3.3.0 0.0.0.255 access-list 4 permit
> > > > > > 163.1.0.0
> > > > > > 0.0.0.255 access-list 4 permit 163.1.3.0 0.0.0.255 access-list 4
> > > > > > permit
> > > > > > 163.1.7.0 0.0.0.255 !
> > > > > > route-map DEFAULTROUTE permit 10
> > > > > > match interface Ethernet0/1
> > > > > > !
> > > > > > !
> > > > > > !
> > > > > > control-plane
> > > > > >
> > > > > > !
> > > > > > !
> > > > > > line con 0
> > > > > > exec-timeout 0 0
> > > > > > privilege level 15
> > > > > > logging synchronous
> > > > > > line aux 0
> > > > > > exec-timeout 0 0
> > > > > > privilege level 15
> > > > > > line vty 0 4
> > > > > > password cisco
> > > > > > login
> > > > > > !
> > > > > > !
> > > > > > end
> > > > > >
> > > > > > _______________________________________________________________________
> > > > > >
> > > > > > Subscription information may be found at:
> > > > > > http://www.groupstudy.com/list/CCIELab.html
> > > > > >
> > > > > > --------------------------------------------------------
> > > > > >
> > > > > > NOTICE: If received in error, please destroy and notify sender.
> > > > > > Sender does not intend to waive confidentiality or privilege. Use of this
> > > > > > email is prohibited when received in error.
> > > > > >
> > > > > >
> > > > > > _______________________________________________________________________
> > > > > > Subscription information may be found at:
> > > > > > http://www.groupstudy.com/list/CCIELab.html
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> > > >
> > > > --
> > > >
> > > > Dane Newman
> > > > MCSE: Messaging, CCNP, CCEA
> > > >
> > >
> > >
> > >
> >
> >
>
>
> --
> Dane Newman
> MCSE: Messaging, CCNP, CCEA
This archive was generated by hypermail 2.1.4 : Tue Jan 01 2008 - 12:04:30 ARST