Double TNS datagrams in one TCP packet
I have the following Problem:
During a database Connection over an IPSec - tunnel between a Fortigate and a Juniper firewall the connection stalls.
This is exactly reproducible with on select or bulk insert statement. Neither OCI or thin changes the behavior. Without the tunnel(f.e. LAN or ISDN connect)
there no problem an no duplicate TNS.
I have logged the TCP traffic with wireshark on both sides and noticed that I have two tns datagrams in one TCP packet.
I use different IPSec tunnels and haven only problems with this one. Do you have a hint whats going on?
BTW: I change sdu and tdu sizes. This changes the point in time of the stall (double tns).
Here is the Wireshark Log:
519 1128.135566 192.168.197.33 10.4.100.73 TNS Request, Data (6), Data
520 1128.135912 192.168.197.33 10.4.100.73 TNS Request, Data (6), Data
521 1128.179202 10.4.100.73 192.168.197.33 TCP [TCP Window Update] ncube-lm > 64542 [ACK] Seq=7203 Ack=2341 Win=65535 Len=0
522 1128.202975 10.4.100.73 192.168.197.33 TCP ncube-lm > 64542 [ACK] Seq=7203 Ack=3691 Win=64185 Len=0
523 1128.213284 10.4.100.73 192.168.197.33 TNS Response, Marker (12), Attention
524 1128.213516 10.4.100.73 192.168.197.33 TNS Response, Marker (12), Attention
525 1128.213557 192.168.197.33 10.4.100.73 TCP 64542 > ncube-lm [ACK] Seq=4265 Ack=7225 Win=64201 Len=0
526 1128.217649 192.168.197.33 10.4.100.73 TNS Request, Marker (12), Attention
527 1128.255460 10.4.100.73 192.168.197.33 TCP [TCP Dup ACK 524#1] ncube-lm > 64542 [ACK] Seq=7225 Ack=3691 Win=65535 Len=0
* 528 1128.501575 192.168.197.33 10.4.100.73 TNS [TCP Retransmission] Request, Marker (12), Attention
529 1128.588704 10.4.100.73 192.168.197.33 TCP ncube-lm > 64542 [ACK] Seq=7225 Ack=4276 Win=64950 Len=0
Here the connection stalls, but does not terminate. The data transmission is not finished.
The * packet has the following header information:
Frame 528: 639 bytes on wire (5112 bits), 639 bytes captured (5112 bits)
Ethernet II, Src: FujitsuT_92:f0:b5 (00:19:99:92:f0:b5), Dst: Fortinet_25:ea:de (00:09:0f:25:ea:de)
Internet Protocol, Src: 192.168.197.33 (192.168.197.33), Dst: 10.4.100.73 (10.4.100.73)
Transmission Control Protocol, Src Port: 64542 (64542), Dst Port: ncube-lm (1521), Seq: 3691, Ack: 7225, Len: 585
Transparent Network Substrate Protocol
Packet Length: 574
Packet Checksum: 0x0000
Packet Type: Data (6)
Reserved Byte: 00
Header Checksum: 0x0000
Data
Transparent Network Substrate Protocol
Packet Length: 11
Packet Checksum: 0x0000
Packet Type: Marker (12)
Reserved Byte: 00
Header Checksum: 0x0000
Attention
Marker Type: Data Marker - 1 Data Bytes (0x01)
Marker Data Byte: 0x00
Marker Data Byte: 0x02
Any idea?