Eastham set for Carlisle
"Ashley is another that we have watched and heard good things about," Carlisle boss Greg Abbott told the club website.
"He enjoyed playing first-team football last season and he comes here ready to show everyone what he can do."
Abbott added: "As we said before, we need cover in our defensive areas at the moment and he will provide that, as well as adding to the competition for a starting place.
"We think we've got ourselves another good signing and we are looking forward to working with him."
Eastham's arrival follows that of Guadeloupe international Miguel Comminges from Cardiff City on Wednesday.
Blackpool striker Marlon Harewood is expected to be out for up to six weeks because of a hamstring injury.
Harewood suffered the setback ahead of the Barclays Premier League match against Bolton on Saturday.
Manager Ian Holloway said: "I wanted it to be competitive at the end of training and it went on too long. It was my fault. I'm in the doghouse from the physio. How long is Marlon likely to be out for? Five or six weeks."
Harewood said: "I did it in training on Wednesday. We were doing sprints and I tore my hamstring.
"I can't believe it as I was feeling good and thought I was playing well.
"I'm not a happy man at the moment but I'll keep going and hopefully I'll be back before too long."
Blackpool midfielder Charlie Adam has won his battle with the club over an unpaid bonus, the Premier League have announced.
However crucially for manager Ian Holloway the terms of the player's contract have not been breached. There were fears the influential Scotland international would have been entitled to leave as a free agent if that had been the case.
In a statement, the Premier League said: "A Board appeal hearing, convened under Premier League rules, was held on Thursday, November 4 to consider a dispute between Blackpool FC and Charles Adam. The Appeal Board found in favour of Mr Adam in relation to the bonus payment but deemed the non-payment was not a repudiatory breach of the player's contract."
At 24 Adams has become Blackpool's most valuable asset in their first season in the Premier League.
The club captain has weighed in with three goals after scoring 18 in the second tier following his arrival from Rangers.
He first arrived at Bloomfield Road in January 2009 before sealing a permanent deal and then led the side to an unexpected promotion.
Rams say Varney exit not sealed.
Derby County have denied a deal has already been done to make Luke Varney's loan move to Blackpool permanent for a cut-price fee of £250,000 in January.Seasiders boss Ian Holloway has claimed that the Premier League side have an exclusive agreement to sign the striker when the transfer window re-opens.
But the Rams insist Varney, 28, can be sold to any club and that no deal is in place with Blackpool.
Varney moved to Bloomfield Road on a season-long loan in August.
He has scored four goals in 10 starts for Blackpool and Holloway has made it clear he wants to keep the former Charlton forward.