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loopback subnet access by virtual instance NOT allowed

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We are working on a new version of our ETM application which requires and assumes full access
the 127.0.0.0 subnet on the AXP virtual instance.
 
Namely, we use
specific addresses such as:
 
127.0.0.2
127.0.0.86
127.0.50.*
 
For inter
process communication.
 
We just loaded
it on AXP and these all fail except 127.0.0.2. Reading the terse description in the devel
guide I see that 127.0.0.2 is assigned to the instance by the host and the rest
of LO is off limits!
 
We need to BIND
application sockets and have communication to/from the above addresses.
 
We are running
our applications with full capabilities:
 
@CCAPABILITIES=
UTSNAME
RLIMIT
RAW_ICMP
SYSLOG
SECURE_MOUNT
@BCAPABILITIES=
SYS_NICE
NET_ADMIN
SYS_TIME
NET_RAW
IPC_LOCK
SYS_BOOT
@PROCFS=
/proc/sys/net/ipv4/ip_forward
0
@MODULES=
ip_tables.ko
iptable_filter.ko
 
We have made assumptions that LO was side
open on AXP since its running a vanilla CentOS 5.2 and NET_ADMIN was set.
 
Is there any
mechanism to enable socket on these addresses? If not, we are in a bit of a
disaster scenario here since its seems that LO is now locked down bug time.
I¿ve tried everything. We assumed using NET_ADMIN gave us full rights to
network mgt.!
 
-J

Hi Jacek,

Please provide additional detail regarding the failure you are experiencing along with your steps for usage. Are you trying to create the desired interfaces as well via the CLI?

There is a special privilege that we provide and is mentioned in our Advanced Features Guide called "CISCO_ADVANCED_NET_ADMIN". This flag is entered into your capabilities file as shown below. This capability will allow you to have full network control and to create interfaces, but they must be done via the linux environment using ifconfig.

@CISCO_FLAGS=
CISCO_ADVANCED_NET_ADMIN


Thanks,

Brett

In Linux it is not explicitly required to create lo subinterfaces because applications can bind to any 127/8 address with no issue.

I understand AXP managed lo differently at the host level with prevents this function.

So, I was trying to use ifconfig to create subinterfaces and received

SIOCSIFFLAGS: Cannot assign requested address

in all cases which prompted me to open this issue here.

I will try the AXP CLI as well as your proposed solution.

creating subinterfaces under the lo subnet via the AXP CLI is not supported.

Jacek,

If you are still having issues connecting to the 127 network IPs on AXP after installing/upgrading your application with the suggested privilege please send over the tech-support logs.

Thanks,

Brett